Millipedes vs. Centipedes: What’s the Difference?

As a kid, the only difference I knew between centipedes and millipedes, was that centipedes had 100 legs and millipedes had a shudder-inducing 1,000 legs. The reality is that centipedes and millipedes are quite different in appearance, size and diet, but seem to get grouped together due to their shared affinity for damp, dark spaces in and around your home.

No matter what you call them (creepy-crawlies, insect invaders), centipedes and millipedes are guests no one invites to their home. While neither carries disease or causes damage, there are ways to keep them outside where they belong. Read on to learn more about these many-legged pests with help from Danielle Restuccia, Division Technical Services Manager for Orkin’s Northeast Division.          

Centipedes vs. Millipedes

Centipedes come in a variety of sizes. The bodies of some species are as small as 1/4 inch in length, whereas others, such as the giant desert centipede, can reach a length of eight inches. Their body is made up of segments, each with a pair of legs. Poison claws on their front pair of legs are used to paralyze prey. Centipedes are generally dark brown, yellowish or reddish in color, and they feast on small insects, spiders and earthworms. They live in dark, moist areas such as under sticks and rocks, along with basements and bathrooms. Here’s a list of different types of centipedes you’ll find in your house.

Millipedes can be up to 1-1/2-inches long and have two pairs of legs on each body segment. They are brown to black, and like to eat organic materials and some young plants. While still fast, millipedes are generally smaller than centipedes. They live in wet areas such as damp basements and bathrooms, and in landscaping such as leaves and mulch.

How to Keep Centipedes and Millipedes Away

“Homeowners who notice more centipedes and millipedes in the home should take the time to check for entry points like cracks, gaps and holes in the foundation, as well as poorly sealed windows and doors,” Restuccia says. 

Since both live in moist areas, you may have a moisture problem. Remove any organic material within a few feet of your home, such as mulch, ground cover and wood chips. Store firewood away from your home as this can be a breeding ground. Make sure all windows and doors are sealed. “Millipedes can become more active indoors after heavy rain,” Restuccia says. 

I recommend not killing house centipedes since they are known to eat other unwelcome pests in and around your home. If centipedes and millipedes give you the creeps, you can get rid of them with an insecticide applied around the foundation of your home. Alternatively, if they have made it inside, sweep or vacuum them up.

“While centipedes and millipedes look intimidating, they are rarely harmful to humans or pets,” Restuccia says. “Overall, it is unlikely to have a dangerous encounter with these pests.” 

FAQ

Are they helpful or harmful in the garden?

Both can be beneficial in the garden unless populations get too large and begin to eat healthy plant roots and seedlings.

Which one is more common in homes?

The house centipede is the species you are most likely to see in your home, especially in the living space.

About the Expert

• Danielle Restuccia is Division Technical Services Manager for Orkin’s Northeast Division.