Rain often dampens millipedes

A graphic of millipedes
A graphic of millipedes Special to the Sun Herald

Many people refer to them as “rainworms.”

Rain can have a significant effect on their behavior but they’re not worms. They’re millipedes. Millipedes means 1,000 legs and it can sometimes look as if they really do have that many. However, the maximum ever counted was just over 700 from a specimen from Africa.

Millipedes aren’t venomous. But you should wear gloves when handling them. They have glands that can secrete a smelly, irritating fluid when they are disturbed.They don’t bite people nor carry any communicable diseases. Only rarely do they feed on live plants. Millipedes are primary decomposers and feed almost exclusively on decaying organic material, turning it into a useful fertilizer. They spend the majority of their lives under the soil or in leaf litter or mulch.

A lot of rain can force these creatures out of their preferred habitat, driving them onto carports, sidewalks, garages and homes. The dame is true with extreme drought conditions. They may survive their sojourn onto carports and sidewalks, but once inside our air conditioned caves, they quickly desiccate and die.

For those of you who can’t tolerate the time it takes to mummify millipedes, here’s three steps you can use.

▪ 1. Exclusion. Caulk and seal all obvious gaps through which millipedes can get in. Check your doors and windows for cracks and crevices and install door sweeps.

▪ 2. Sanitation. This means getting rid of debris and objects near the house that offer millipedes a place to hide. This includes boards on the ground, compost piles, leaf piles stacks of wood or general trash. Mulch in your flower beds should also be checked. Use the least amount of mulch needed to do the job.

▪ 3. Insecticides. Controlling millipedes with insecticides is problematic at best and isn’t something I’d recommend. The most common reason why insecticides fail against millipedes is lack of volume. It takes around one gallon per 100 square feet to reach them where they live.

That’s a lot of chemical. If you want to use an insecticide, a hose-end applicator is best. Saturate the soil around the base of your house about two meters out from the foundation and another meter up the wall. Any of the insecticides labelled for use on your lawn should do the job.

Inside the house, don’t do anything. Millipedes will die within 24 hours on wandering inside. Just vacuum up their carcasses when you see them. For the most part, leave the little guys alone. After all, they’re supplying your yard and garden with free fertilizer.

Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.