Although centipedes and millipedes both prefer similar habitats and have elongated bodies with a disturbing number of legs, they are more unalike than they are alike.
Millipedes, also known as thousand-legged worms, have round, brown to black, worm-like bodies with short antennae and short legs located underneath their bodies. Though worm-like in appearance, millipedes have segmented bodies with two pairs of legs attached to each segment, with the exception of the first three, which only have one pair of legs each. Although some species are larger, they usually range from one to two inches long, and they actually have 80 to 400 legs, not the 1,000 that their nickname claims they have.
They are burrowing scavengers who feed on decaying leaves, wood, and other plant material. In general, millipedes are valued garden inhabitants whose diet gives them a role in aiding decomposition and raising nutrient levels in the soil. However, they do sometimes feast on the leaves and roots of newly sprouting seedling, which is not appreciated.
Millipedes are slow movers whose somewhat rigid bodies ripple or take on a wave-like motion when they walk because of the length and positioning of their legs. As scavengers, millipedes are not poisonous, and they do not bite or sting.
When threatened, millipedes curl up into a ball. As protection from predators, they can also secrete or squirt a foul-smelling, noxious chemical from glands along their bodies. That chemical is caustic and can actually produce mild burns or a burning sensation on your skin or in your eyes.
Centipedes, also known as hundred-legged worms, have flatter bodies than millipedes, and they range in color from yellow to reddish orange to brown. In length, they can range from one-eighth to six inches. They have much longer antennae than millipedes, and one pair of long legs per body segment — 15 to 177 pairs of legs. Those legs, which are attached at the sides of the body, allow centipedes to run much faster than the millipede.
Unlike foraging millipedes, centipedes are predators. Their antennae allow them to hunt by scent and touch, and their fast-moving legs and flexible bodies allow them to capture their prey, including spiders, worms, insects like cockroaches, and even other arthropods such as millipedes and other centipedes.
Because they feed on insect pests, centipedes can be beneficial, however, because they are predators, they are also poisonous. Millipedes always have an odd number of leg pairs because their first pair of legs are modified into claws that contain venom-producing glands, allowing them to grasp their prey while injecting the venom. A centipede bite is not generally dangerous to humans, however, the bites are painful, comparable to a bee sting. Children and those who are allergic to other insect bites and stings can have allergic reactions to centipedes as well.
Neither millipedes or centipedes have the waxy coating that protects other insects and arachnids from losing moisture through their exoskeletons. For that reason, both seek damp, outdoor environments. You will most likely find them under rocks or logs, in mulch, or under loose bark, fallen leaves, or other organic debris. However, if it is overly damp outside, centipedes and millipedes may seek shelter in dark, damp areas of your home, such as your basement, kitchen, or bathroom. Also, like birds, millipedes may migrate long distances in the spring and fall. Large numbers of them may invade at those times. Discourage them by repairing leaks, using dehumidifiers, sealing cracks in your foundation, removing mulch and wood piles from areas near your home, and eliminating sources of prey for centipedes.
Centipedes and millipedes may have legs and habitats in common, but not much else.
If you have an issue with either of these pests invading your home, make sure to call a pest control professional like UltraPro Pest Protection right away to get them out before they cause too much damage.