Here’s some pest biology about centipedes and millipedes! The main reason I want to share the differences of the two is because centipedes can potentially be harmful to people whereas millipedes are actually pretty tame creatures.
A lot people will commonly find a centipede or millipede in their homes and start freaking out. I’m not surprised! Both bugs are so creepy with what seems like hundreds and hundreds of legs. Even though they basically move the same way and look very similar, theres some major differences in the two creepy-crawlies.
First is the shape and physical appearance of the two. Both are multi-segmented arthropods. Centipedes have a flat shape to their bodies and are lighter in color whereas millipedes have a cylindrical shape and are typically darker in color. They both have several pairs of legs attached to their bodies but centipedes have one pair of legs per segment and millipedes have two pairs. If you look close enough and compare the two side by side, you’ll also notice that even though they both have antennae, the centipede’s antennae are significantly longer than the antennae of millipedes.
Another difference between the two are there ways of movement. Centipedes are extremely active and are actually known for their speed. However, millipedes are known to be slow moving. Centipedes are also very flexible and millipedes are inflexible.
Also, their food sources are also very different. Centipedes are actually carnivorous and feed on other small arthropods. Millipedes, however, are detritivores, which means they consume decomposing matter. With this in mind, their defense mechanisms and tactics will be different. Centipedes have stinging structures on the front of their heads that they use to kill their prey or use to bite when they feel threatened. Likewise, if handled incorrectly, centipedes have the ability to bite people. Millipedes, on the other hand, do not have these structures nor do they bite. As a defense mechanism, they emit secretions from defensive glands on their bodies and are known to roll up like their cousins, the pill bugs. They do not bite people, however, the more exotic species may squirt their secretions which handlers should be cautious of.
Lastly, although both centipedes and millipedes habituate in moist areas, centipedes actually have a broad spectrum of habitats. Millipedes however, only thrive where moisture is optimal.