Rains drive millipede menace into homes

Victorian homes are being invaded by black Portuguese millipedes revelling in ideal conditions created by recent rains.

The critters are being seen in their largest numbers in eight years, says Melbourne Zoo's invertebrates specialist, Patrick Honan.

The recent wet weather had created an abundance of food for the imported pest, which was accidentally introduced to Adelaide in 1953 and has now spread across southern Australia.

"They increase in numbers every autumn and every spring across most of southern Australia, but in Victoria this year we have had a particularly wet patch and that really encourages them. This would be the worst we have seen for seven to eight years," Mr Honan said.

He said the millipedes, which are smooth and cylindrical and between 2-4.5cm long, secreted the chemical hydrogen cyanide when they were disturbed or squashed.

While not dangerous to humans in small quantities, the chemical stains anything it comes into contact with and is extremely irritating to eyes.


"It's a very effective defence because they will stain some things permanently," Mr Honan said.

"The best thing to do is to not squish them. If you can, sweep them up and put them outside. They actually don't like being inside and certainly don't breed inside but they come inside because often there's just so many of them."

A plague of black Portuguese millipedes overran railway tracks at Tallarook, central Victoria, last March, resulting in several train cancellations.

"When the trains run over them they get squashed and can interfere with our signalling because the equipment is so sensitive," a railway spokesman said.