mooseFlickr / Al_HikesAZNot the alcoholic moose in question.

Humans aren't the only angry drunks out there. Alcohol use by animals shows up frequently in nature, too. 

For example, Sweden's drunken moose (or possibly elk, according to another report) gang season is just beginning. In the fall, ripe fruit falls to the ground and ferments, giving even the giant moose enough alcohol to get a good buzz on.

A few weeks ago a Stockholm police incident report stated that a mob of the boozed-up moose — four adults and one calf — had been terrorizing a local homeowner after he refused to let them into his garden.

The Local talked to the policeman who filed the report: "I'm not surprised that he called the police when he was faced with a gang of five drunken elk," police spokesman Albin Näverberg told The Local. "They can be really dangerous. They become fearless. Instead of backing away when a person approaches, they move toward you. They may even take a run at you."

The boozy animals left the scene when the police showed up, according to the Alaska Dispatch. A similar story made news in 2011 when a drunk moose ended up stuck in a tree

Drunk animals aren't all that rare. The sugars in fruits are naturally turned into alcohols by fungus that feast on them. In the Stockholm case, the fruit in question was likely apples from the homeowner's tree. Even fruit flies get drunk — and get rid of parasites while they do it.

While a Scientific American story from 2008 claims to find scant evidence that animals like to get drunk in the wild, other anecdotal stories abound. Mother Nature News claims to have found five creatures who love getting drunk, including elephants and bears.

The reports of drunk elephants seem to be exaggerated, though. While the animals do eat alcoholic fruits from the Marula Tree in the wild, they don't eat nearly enough to get them drunk — that would take between 2.5 and 7 gallons of the fruit.

Some animals are used to the naturally occurring alcohols in fermented fruit, and even intentionally seek it out. One species of shrew can "drink" all night without ill effects, as can some fruit bats.

Not all animals get drunk naturally, though. Over the weekend feral pig was spotted ravaging a Western Australian campsite for beers. After stealing what was reported as 18 beers from campers, the pig was seen getting into a fight with a cow, according to ABC News.