Centipedes, millipedes, sowbugs, and pillbugs are arthropods (not insects), although they do enjoy the same living conditions as insects. These creatures are not harmful. They are merely unattractive and considered a nuisance, especially when found indoors.
Although all centipedes have poison glands that open through their jaws, most house centipedes are not able to penetrate human skin with a bite. However, the few that can will give an effect similar to a mild bee sting, with symptoms generally disappearing within a few hours. The house centipede’s bite will not cause any serious harm to pets like dogs and cats.
Sowbugs and pillbugs can sometimes enter damp areas of your house in large numbers. However, they do not bite, sting, or transmit diseases, and they don’t infest food, clothing, or wood.
Sowbugs, pillbugs, and millipedes break down organic matter, releasing nutrients to garden plants. Centipedes help control other insect pests. For these reasons, this group can be considered beneficial and should be tolerated as much as possible.
A persistent infestation of sowbugs, pillbugs, or millipedes indoors may indicate a serious moisture problem within your home, and the presence of a food source like rotting wood.
Snowbugs and Pillbugs
Sowbugs and pillbugs are less than 2 cm (.79 inches) long and are usually dark to slate gray. They are armadillo-like and belong to the same class of animals as lobsters and shrimps. These tiny land crustaceans need moist conditions to survive, and like to live under rocks or debris where they feed on decaying organic matter. They usually die quickly once inside homes because moisture levels are not high enough for them.
Millipedes and Centipedes
Wormlike millipedes and centipedes both have many body sections and many legs. However, the centipede has a more flattened body and only one pair of legs per section, while the millipede’s body is rounded on top with two pairs of legs per section. Also, the centipede’s legs are much longer, allowing it to move more quickly. When disturbed, millipedes tend to coil up, but centipedes swiftly run for the closest dark hiding place.
Centipedes are an efficient way of controlling other insect pests in your home.They like to eat spiders, bed bugs, cockroaches, silverfish, carpet beetles, or ants. Millipedes, on the other hand, do not survive once in the home because it is too dry for them.