Centipedes and millipedes are grouped together because they both have segmented bodies and prefer to live in the dark, but the two appear very differently. Centipedes have longer legs, with only one pair of legs on each body segment. Conversely, millipedes have very short, stubby legs, with two pairs of legs on each body segment. Centipedes are predators that eat smaller insects, and while they do have a venomous bite, centipede bites are not harmful to humans. Millipedes scavenge for decomposing plant matter like dead leaves and decaying wood. Centipedes are flat and stay close to the wall, biting if a human gets too close and speeding away as fast as possible.

Millipedes are rounded, resembling a caterpillar or a worm, and they will curl up into a ball and release a foul-smelling chemical when threatened. One of the biggest differences between these two is where you will encounter them. Centipedes prefer dark, secluded areas with plenty of insects to capture and eat, so you might find centipedes inside your basement, closet, crawl space, or anywhere else where insects may tread. Millipedes need a lot of moisture to survive, and even the most humid homes cannot sustain them for long, as these bugs often spend their entire lives in the soil. Because of this, you will often find millipedes outside in your yard or garden. Millipedes will only migrate into homes after periods of heavy rainfall when the soil becomes too saturated to live in. However, most millipedes die after migrating indoors, and you might find their bodies curled up in your carpet.