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Dear AskAnt team

I would really appreciate it if you could identify this ant for me.

I am located NEE of Johannesburg,South Africa, and these ants are all over my garden - under the paving. (I also have an infestation of termites.)

They are 2.5 mm in length while the major workers are about 4.5mm. They are more dark brown than black .

They seem to go for things like crumbs, odd bits of nuts, egg, meat and dead insects that may end up on the floor - they do not go for my sugar bowl or anything else that is sweet.

Much appreciated,
Marj, Johannesburg
Ant hill 1.jpgAnt 1.jpgAnt hill 2.jpgAnts_egg.jpgAnts_flower.jpgAnts_insect.jpgMajor worker.jpg

Hello Marj

We contacted an ant expert and friend in Pretoria, South Africa, Peter Hawkes, and he responds:

Looks like good old Pheidole megacephala - the only other possibility would be Pheidole tenuinodis, which also occurs in the region (not possible to tell the difference from these pictures, but in my experience it is almost invariably P. megacephala that becomes problematic in this area).

P. megacephala is one of the two commonly annoying ants in Gauteng (the other is Lepisiota incisa); they handle disturbance very well and can completely dominate the fauna of a property. If control is needed a slow but effective method is AntTraps (placed near the nest entrances) which contain a bait that is carried back to the nest and kills off the queens (of which there may be hundreds). Eventually the colonies die out, though this may take several months, possibly requiring replacement of the traps for big infestations, and involves a rather distressing phase where thousands of disoriented workers (both major and minor) mill around on the surface, apparently having lost direction after all the queens have died....the advantages are that it is very directed, affecting only the targeted colonies and leaving the rest of the ant (and other insect) fauna unharmed, and seems to have a longer-term effect than other methods such as applying liquid poisons into the nests.

Brian Fisher and the Ask AntWeb team

Weaver Ant Farming

Dear AntAsk Team,

Weaver ant larvae is a commodity here in Indonesia, we use weaver ant larvae for dietary supplement to improve the performance of songbirds before bird singing competition and carp fishing bait. Throughout the year weaver ant larvae is harvested and sold, because demand for weaver ant larvae has increased in recent years some areas are being over harvested and as a result diminishing in weaver ant colony in the nature.
From that point, I and some friends trying to establish a weaver ant farm so we could meet the demand for weaver ant larvae and by doing so also help to reduce over harvesting in the nature.

Right now we have 42 jar of weaver ant nest in our colony which started from 30 jar of nest (the farming have started 1.5 month ago).
The diet of our farm is sugar water, caterpillar, crickets, diluted honey, diluted white egg, diluted fish oil.
Note: we haven't tried to harvest the larvae. Attached pictures of our farm setup.

DSC_0007.JPG DSC_0195.JPG

My question is:
1. Is it true that weaver ant tend to grow in population the most in shaded or dark places(because of these rumor we build a shed using paranet)?
2. What diet is the best for weaver ant to produce more egg?
3. After 1.5 month from the initial start now our weaver ant produce less and less egg what could go wrong?
4. How to join the antblog? I registered but there is no confirmation e-mail for activation.
Thank You in advance. I apologize if I'm not courteous enough or there is any mistaken words since English is not my native language.

Best Regards,


Hello Mario,

Thanks for your questions, and congratulations on your initiative: edible insects are the way to go!

We contacted an expert on many aspects of Oecophylla biology, Dr. Joachim Offenberg; and here is what he had to say:

"1. In nature they prefer sunny places for their leaf nests. However, as it looks like you keep the ants in plastic bottles it may be better under shady conditions as the bottles are transparent and temperature may build if exposed to direct sunshine. You can find a study on this issue via this link. On the other hand, the ants prefer temperatures usually above 30 degrees Celsius. Brood development increases with temperature.

2. The diet you describe seems to be adequate for the ants but it is important they have ad libitum access to a 20-30% sugar solution (they seem to prefer sucrose) and also remember to provide pure water ad libitum. In general they accept most types of protein but they prefer it in a wet condition. I.e. fresh rather than dried meat and fish etc. As insects are their natural source of protein it think it would be wise to include insects to some extend in their protein diet.

3. First of all you need to be sure that you do not mix nests from different colonies. In that case they will fight each other rather than producing offspring. Secondly you need to be sure that the maternal queen of the colony is included in your ant farm. The maternal queen (the queen without wings) is the only member of the colony that can produce eggs that are able to develop into brood. Weaver ant colonies will not accept introduced queens which makes it important to find the maternal queen of the colony (which can be difficult!). A last reason for limited brood production could be limited availability of space in the ant farm. I know from my laboratory colonies that colonies that live under limited space, reduce the production of new workers, since the colony is able to match the production of new workers to their actual need. I do not, yet, know the mechanism behind this regulation and have therefore not found a way to trick them to continue a high brood production. If you find a way I will be happy to hear about it!

4. Lastly, it is important to protect the ant farm against smaller ant spices as e.g. Pheidole spp., crazy ants etc. They like weaver ant larvae as much as the birds and are in many cases able to win a fight against weaver ants.

Good luck with your ant farm and best wishes,"

Joachim Offenberg, Flavia Esteves & the AntAsk Team

p.s. Mario, you began your AntBlog membership when you sent your questions to us! We really appreciated that, and hope to hear more interesting questions from you soon!
p.p.s. Your English is great!

We have had ant problems in the house every spring and summer and have had good success in getting rid of them by using Terro. It is now September and we have a new wave coming inside but this time of year they are not going to the Terro. What is the reason for this?


Dear Dean,

Greetings from the ant world!

Baits contain poison mixed with materials that attract ant foragers (i.e., worker ants looking for food or water). The ants will take small poisoned portions back to the nest (and eventually transferred to other nestmates, including the queen), and those will kill the entire colony.

Key points to use poisoned baits correctly:

1. The intoxicant used must be slow-acting, so the foraging ants have time to make their way back to the nest and feed other members of the colony before they are killed. Pre-packaged bait stations (like Terro) usually contain 5.4% borate, and they efficiently kill foragers in the home, but will take effect too soon and leave the queen(s) unaffected. Liquid borate products (derivate from Boric acid) with a lower percentage of active ingredient -- less than 1% of the active ingredient -- will have more impact on the colony, although it may take several days to a week to see results and they need to be used in larger, refillable bait stations.

2. Effectiveness of baits will vary with ant species; bait material, and availability of alternative food. Ant preferences, for example, can change throughout the year; to increase your success rate, set out different formulations of various bait products in a single baiting station, giving ants a choice. It would be something like a "cafeteria": simply line up a few drops (liquid foods are preferable because you can mix them evenly with the poison) of different kinds of food on some wax paper, and see what the ants go for (you can use peanut butter, sugary solutions, and pureed tuna fish).

3. Don't use any insecticide sprays while you are using baits, and check and refresh bait stations regularly. Baits can dry up or become rancid and unattractive over time. Also, to improve bait effectiveness, be sure to remove any particles of food, residues of sweet liquids, or other attractive material from cracks around sinks, pantries, and other ant-infested areas.

However, we, AntBlog people, just love ants - they are really amazing creatures, and have a lot to offer to our society (see here). Ants are, most of the time, good roommates, and will keep other insects out of your house; and you can observe, in the comfort of your home, how they interact with each other! Also, poison baits in your house will be a permanent risk for children and pets, and it can also contaminate wildlife and water supplies. If the ants in your house are unbearable, you can seal the cracks where the they are entering, vacuum up the ants, and apply boiling water in the nest entrance.

We hope this helps,

Flavia Esteves & the AntAsk Team

Hello, I am in Toronto and have located a colony of small reddish/brown ants living under the 6x6 wooden ties surrounding my lawn. My question is: are these ants beneficial to the eco-system and should therefore be simply left alone? I have a wooden porch: should I be concerned about 'an invasion'?
Secondly, I have occasionally seen the same type of ants moving in mass across sidewalks - thousands of them - so many that it looks like a brown stain on the sidewalk. Can you tell me what causes this phenomenon?
Thanks for your help,


Dear Mary,

Thanks for writing to the AntBlog! It was a pleasure to answer to your interesting questions.

Ants play a huge role in an ecosystem: they are diverse (we estimate 30,000 ant species living on Earth), and are in great numbers everywhere (all the ants weigh almost the same as the 7 billion human beings). Along their evolution, ants established ecological relationships with a large array of plants and animals. They are prey, predators, symbionts, parasites (there are even slave maker ant species!), seed dispersers, pollinators, and so on. Ants move more soil than earthworms. They impact and are impacted by almost everything surrounding them. More, they have a short lifespan, and that means their nest population is constantly being replace by new generations of ants. So, if something happens with an environment you will notice the effects faster and with more details if you look at the ants, and it will be much more effective than looking at birds or mammals, for example.

Just for curiosity, ants are important for other aspects of human societies. Their behavior is used as model to create smarter traffic lights, or to develop software that will evaluate the response of our bodies to the effect of new drugs (see here, here, and here). Anti-inflammatories, antibiotics, and even drugs to fight against cancer were/are being developed with substances ants secrete (here, here, here, here, and here). Finally, have you ever thought of including ants in your menu? Many human cultures around the world did! See here.

Salad of Oecophylla smaragdina queen brood mixed with some worker ants, mint leaves, spring onion, chili, and fish sauce. Popular in Thailand and Laos. Image by Joost Van Itterbeeck/

Based on the behavior you described, I believe you found pavement ants (genus Tetramorium). Unlike carpenter ants (genus Camponotus), pavement ants don't cause any structural damage to your house (and just to take Camponotus out of the fire, those ants nest in decayed wood; so, if the wood in your house is in a good shape, carpenter ants will not be a problem).

Pavement ants get their name because they nest usually underneath or at the edge of sidewalks, and other hard surfaces. They are an introduced species from Europe; and in your garden they will: harvest seeds -- some of which will eventually grow around their nests; tend insects on plants, collecting sugary dropping they produce (A.K.A honeydew), and protecting them from predators; and predate other insects.

The pavement ant workers are dark reddish-black, about 2.5-4 mm long; the petiole, which connects the mesosoma (i.e., the modified thorax of ants) and gaster (modified abdomen), has two segments. The posterior part of the mesosoma has two spines that project upward, and they have a stinger in the last abdominal segment.

Lateral view of Tetramorium caespitum. Image by Will Ericson/

When two pavement ant colonies overlap, worker ants leave the nest to establish their territory boundaries before ants from the other nest push them out of there. Then, ants coming from each nest collide in a massive battle. The combats are sometimes ritualized: they will just size each other strength, and produce very few casualties. In another occasions, they will ripe one another apart, and thousands of corpses will be left on the sidewalk afterwards.

Sidewalk ant war. Image by the fabulous Alex Wild (


Flavia Esteves and the AntAsk Team

We have a sudden ant infestation. Nothing works to get rid of them so we are going to ride it out I guess. Must be the drought in California? I have a question though. They often congregate in our shower. Even when and especially when it is dry in there and no one has showered since the morning. Today, I went in and there were a number of trails leading to perfectly formed circles. The circles had the ants facing inwards and their bodies/tail ends pointing outwards. I wish I would have taken a picture but I was upset and I washed them away. It wasn't a moving circle. It was a stationary size of about a nickel circle. Much like a synchronized swimming event. Is this a meaningful event? Are they talking about leaving my house in this circle? I sure hope so. Thanks for answering me or replying back to my email if you have time. Oh and they are small little black ants - if that matters.


Dear Mary

The ant that is visiting your house is most likely the argentine ant. The move inside when it is too dry outside or too wet. As you have noticed there is many advantages to these visits - one is that you are presented with a convenient chance to observe nature in the comfort of your own home. Why are they forming a circle - well there must have been some resource there - residue from the evaporated water (salts most likely) that the ants were feeding on. If inclined you could give them a drops of water with food coloring in them and watch them change colors:


You can read more about the sudden movement of the argentine ants into homes in California at:

With regard to control, I strongly advise a green approach. First, seal the cracks where the ants are entering. Next if the ants in the house are a problem, then just vacuum them up. Outside if you want to control the nest, apply boiling water (lots of it). Chemicals in your house will be a permanent risk to you and others and outside when applies will be a containment to wildlife and water supplies.

Best, Brian Fisher and the Ask AntWeb Team

Ants in an ant hill

How many ants are in one ant hill?


Dear Samir,

Thanks for your question!

Ants are abundant: they collectively rival with humans as dominant organisms on terrestrial ecosystems, weighing as much as all humans present on Earth; and, combined with termites, they comprise almost a third of animal biomass in tropical terrestrial habitats! The reason for such success is their social nature. More, there are around 16,000 described ants species in the world, and we think there is approximately the same number of species yet to be discovered. As their large species number indicates, ant societies exhibit a diverse array of behavior, morphology, and also nest sizes.

While Myrmoteras barbouri has around 8 individuals in their colonies, some species of nomad ants that live in the old world, A.K.A driver ants, may have nests with several million individuals. Another good example of large nests is the ones built by Atta sexdens, a leaf cutter ant living in the Neotropic, which may possess 5 to 8 million ants!

myrmoteras.jpg Full face view of the charismatic Myrmoteras barbouri, whose nest possesses very few ants. This ant species lives in the Indomalaya bioregion. Image by Estella Ortega/

siafu7-L.jpg Dorylus driver ants in Kibale, Uganda. Image by Alex Wild (

Among the diversity of ants we find on Earth, there are the mound-builder ants. Their nests are more than a pile of revolved soil covering an underground home; they have symmetric shape, complex interconnected systems of galleries and chambers, and are often thatched with leaves and stems fragments, or adorned with pebbles. Those types of nest indicate habitats under extreme climate. The mound reduces the loss of temperature and humidity, while it also increases the area exposed to sunlight, keeping the nest warmer than the outside environment. Their thatched or pebble sprinkled roofs are an additional heat source (think of how warm is a stone under the sunlight, or the heat produced by material in decomposition), besides preventing evaporation.

FormicaObscuripesNest-S.jpg Thatched mound nest of Formica obscuripes, an ant found in North America. Image by Alex Wild (

The nests of some mound-building ants, such as Formica (also known as wood ants), often last for many decades, and they can be massive, rising from the soil surface as much as 5 feet (1.5 meters).

A thatched mound nest of Formica rufa, found in Palearctic region, may have 4 million ants; while in North America, nests of the western thatching ant Formica obscuripes, house around 40,000 ants. The soil mound nests of Solenopsis invicta possess approximately 100,000 individuals.

casent0178134_p_1_high.jpg Lateral view of Solenopsis invicta, a tramp species found in the United States. Image by April Nobile/

You will find interesting information on mound nests and thermoregulation here.

All the best,

Flavia Esteves & the AntAsk Team

Ants and Disease

Hello, this is a very strange situation but I have a 10 month old baby in my home and I am concerned.

A couple of weeks ago I went in to the backyard and noticed my dog was playing with something unfamiliar. As I walked towards it I realized that it was a bird. This bird must have been there for awhile because it was unable to move, and had defecated so much that ants were (I'm sorry for the graphic details) actually crawling inside of this poor bird and apparently eating the fecal matter. This poor guy was obviously in a significant amount of pain so we had to do something very sad to stop it from suffering any longer.

This just so happened to have occurred next to a wall in our home that is the exterior wall to our dining room where we eat and where my 10 month old's high chair is. Today, I was eating at our table and some of my paper work and pens were sitting on top of it. As I was picking up my plate I noticed the same species of tiny little ants crawling all over the table and my paper work. There was not even any food or anything on the table that could have lured them there. I instantly took my son upstairs, and began disinfecting the table, vacuuming and such.

I do not know anything about ants but my concern is that these ants might be carrying disease from the bird. Can you please tell me if I need to be worried about this? They are the tiniest little transparent orangish colored ants. We live on Oahu, in Hawaii. Thank you very much for your time.


Ok, Alix. I've got good news and bad news.

The bad news: Ants (just like any animal that moves from one place to another) can transmit infectious bacteria, including Salmonella and Staphylococcus. (I'm not trying to throw your dog under the bus by any means, but your dog is definitely more of a vector for bacteria coming in from outside than these ants.) As indicated in a quick literature search (click here ), it's been reported at least as far back as 1914 (Wheeler) that if an ant walks through an area densely populated with infectious bacteria, they track it along in quantities large enough to show up in a petri dish.

The good news: Petri dishes don't have immune systems. The quantities of bacteria ants transport and slough off as they saunter across your counter tops will probably be small compared to the infectious dose for healthy humans. The quantities of bacteria that remain on the ants' feet after taking the thousands of little ant-steps between a source of infection and your table would presumably knock off the vast majority of the bacteria, leaving too few to constitute an infectious dose.

So what I'm trying to say is: thought it is theoretically possible for ants to transmit infectious bacteria to humans, as far as I'm aware (other members of this blog, please speak up if you know better!) there are no records of ants being definitively implicated in someone catching a disease. As best as I can tell, all of the articles that reference ants' potential to be vectors for infectious bacteria are based upon laboratory studies in which nothing besides some agar in a petri dish got sick. Ants, as you know, are quite common, so it seems to me that if they were serious actual (as opposed to potential) disease vectors, we'd have heard about it.

A well-intentioned tangent: This is, of course, neither a child-rearing nor a health advice blog, but I think this recent article on the "Hygiene Hypothesis" makes a good case for not keeping too sterile a house:
Some arguments, both pro- and con- Hygiene Hypothesis haven't been rigorously scientifically tested, so take everything you read with a grain of salt...or a pinch of dirt.

Hope this helps!
Jesse Czekanski-Moir & the AntAsk Team

Ants in concrete foundation

Hi - and help!?

We live in Northern Alberta, Canada. Over a year ago, we discovered ants - lots of ants - coming up into our furnace room through a crack in the concrete foundation of our basement. My husband put poison down the crack and seemed to work very well, getting rid of them and not coming back. Until now.

Last night he went to check - as he does periodically - and now they are large ants coming from the same crack in the concrete. He again put poison down the crack, and vacuumed up the few dozen (he may have been lessening the amount to avoid my freak out). My daughter's bedroom
is right beside the furnace room. She went to bed last night - only to be woken up by something flying and hitting her in the guess is a flying queen ant.

Please tell me what we should be doing to ensure we have gotten to the bottom of this ant problem. Should we get the crack filled? Will they find another place to come in? In order to get access to this part of the foundation concrete, they have to be coming in very deep under the back yard as that part of the foundation must be at least 6 feet underground.



Hello Cathi,

Thanks for writing to the AntBlog!

Ants are an important part of the natural world, and play a great role in an ecosystem. Their extreme diversity and abundance, wide spectrum of biology and interaction with other groups of organisms, make them affect the pattern of distribution and abundance of plants and other animals. The good news is that this is also applicable to your home environment: ants will control populations of other housemate arthropods, like spiders, fleas, clothes moths, bed bugs, and so on. We can also learn a great deal with ant behavior (to see how ants have inspired human societies, take a look here).

Full face view of Polyergus breviceps, a slave maker ant species that occur in your area (image by Shannon Hartman/ See more on how it makes slaves here.

So, if it were my home I would just control their population, prevent them from accessing my food, and marvel myself with them crawling around. Procedures like proper food storage and waste management, and daily surface cleaning, will reduce the number of ant workers indoors.

However, if you really cannot live with those wonderful creatures, I think the most effective way to prevent them from accessing your home would be to seal the cracks (you can use clear silicone, or other sealant).
Please, note that commercial sprays are ineffective against ants, killing just the foragers, while the rest of the nest (deep underground) continues intact. Poisoned baits generally work well to eradicate ant colonies (workers feed on the bait and take it back to the nest where they share it with their nestmates), but this approach may take several weeks to several months to produce an effective result. You can read more on baits here.

We hope it helps,

Flavia Esteves & the AntAsk Team

Ant social status

Hi, I was curious if ants have a social status within their sub sectors (worker, male). How do they obtain a higher status? And if so does this give them more privilages (ie a bigger living space, more food, first breeding rights).


Dear Hub,

Thanks for writing to the AntBlog! We contacted an expert on many aspects of ant biology (behavior, colony reproduction, nest architecture, population dynamics, among others), Dr. Walter Tschinkel; here is what he had to say:

"Hello Hubert,
You asked AntBlog whether ant have social status within their colonies, and whether such status might be connected to certain individual advantages and benefits.
The simplest answer is that social status in the sense that we know it within vertebrate societies does not exist in ants. It is helpful to think of ant colonies as analogs to organisms (hence, we often call them superorganisms). Every individual is engaged in helping the colony produce more colonies, just as every cell in an organism is engaged in helping produce more of that organism. In the ants, there is only one (or a few) individual(s) capable of direct reproduction (the queen), while in an organism, only the germ-line cells in the gonads are capable of making gametes and subsequently more organisms. In this light, you can see that different sectors of the colony may be allocated differing amounts of resources, but such allocation serves the needs of the colony as a whole, rather than any individual within it. The individual ants making up the colony are simply the machinery needed to make more colonies.
One of the basic mechanisms that organizes colony function is division of labor (or function). The most basic division of function or labor is reproductive -- most of the ants in a colony are more or less sterile workers, while only one (or a few) individual is capable of mating and laying eggs. Most of these eggs develop into more workers because workers are short-lived and are continuously replaced, whereas the queen has a long life span (in many cases, equal to the life span of the colony). The second principle that organizes the colony is that the workers change jobs as they age. Young workers mostly take care of larvae and pupae, and as they age they switch to more general nest maintenance, food processing, transport within the nest and so on. Only the oldest workers leave the nest to forage, bringing back food for the rest of the colony. Once they begin foraging, their life expectancy is very short (a few weeks).
This change of jobs parallels an upward or outward movement of the worker within the nest. Young workers are born in the deeper parts of the nest, move upward as they age and change jobs, and finally appear near the surface, whereupon they become defenders and foragers during the last part of their lives. There is thus a continuous upward and outward flow of workers. The image here shows a cast of the nest of the Florida harvester ant, Pogonomyrmex badius, and summarizes these movement and labor patterns within the nest.

Once you see the parallels between organisms and superorganisms, you see that division of function or labor is central to both, and that differences in allocation serve the entire entity. The relative size and activity of the liver, or kidneys or circulatory system of an organism serves the entire organism, and any deviation from some norm can be detrimental to the function and fitness of the organism. Similarly, the patterns of division of labor in ant colonies serves the success and fitness of the colony as a whole. The workers are just the gears in that machine."

We hope this answers your question,

Walter Tschinkel, Flavia Esteves & the AntAsk Team

My name is Joseph, a senior biologist at the University of Scranton. I am currently conducting research on morphometric of ants, but we are having some issues. I was curious if you had any papers on the histology of ants, specific on the nervous system or their notochord. Any species will do at the moment, we are just used to looking at mammalian tissue, and not insect samples. Hope to hear back from you soon!


Hello Joseph,

Thanks for writing! We contacted an expert on the nervous system of ants, Dr. Wulfila Gronenberg; here is what he had to say:

"Dear Joseph,

the nervous systems of insects has been well described for many taxa, and ants are no exception. The basic design is not unlike what you see in vertebrates - they have a brain with visual, olfactory, tactile and other centers including higher order central processing centers, and the have a ventral nerve cord analogous (and probably homologous) to the vertebrate spinal cord and which comprises the sensory and motor centers that control walking, flight (in winged males and females) and abdominal functions. If you want to learn more about ant nervous systems I suggest a review paper that I have written a few years ago:

Gronenberg W (2008) Structure and function of ant (Hymenoptera: Formicidae) brains: Strength in numbers. Myrmecological News 11:25-36.

If you (or anybody else) have difficulties getting hold of the paper, just send me an email:
If your question was more about histological and technical aspects (how to dissect, stain or measure ant brains), please let me know and I can point out some more specific information to you.

All the best"

Wulfila Gronenberg, Flavia Esteves & the AntAsk Team

p.s. Joseph, if you create an account on Myrmecological News (for free), you can download Gronenberg's paper.


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