2021 Edit: Narceus americanus is not the largest millipede in North America, but it is among the largest on the continent.
I love bugs, but I am afraid I haven’t given them much love lately, so here’s a little post about some of my favorite bugs, the myriapods. Myriapods (which means “10,000 feet”) are centipedes, millipedes, and other related arthropods. They are the oldest known land animals, and they are NOT insects. In fact, while centipedes and millipedes are more closely related to each other than they are to insects, they could hardly be more different.
First off, centipedes (“100 feet”) have fewer legs, although they don’t always have 100 of them, and millipedes (“1000 feet”) have more legs, but no known millipedes species has anywhere near a thousand. But that’s just scratching the surface. On top of that, centipedes have one pair of legs (two legs) on each segment of their bodies while millipedes have two pairs of legs (four legs) on each segment.
So that’s it, right? They just look a little different? Nope. They also behave differently. Centipedes move very quickly and are primarily carnivorous. To attack and disable their prey, they possess a a pair of modified, venomous claws called forcipules, which are located on their heads. Millipedes, on the other hand, move rather slowly and are primarily detritivores, which means they eat dead plant and animal matter. While they lack venom, they secrete noxious (and occasionally dangerous) chemicals like hydrogen cyanide from microscopic holes in their bodies called ozopores.
Thus, those are the basic differences between centipedes and millipedes. In short, the centipedes are fast, venomous predators with fewer legs, and the millipedes are slower, odorous scavengers with more legs.