Though centipedes inhabit almost every corner of the Earth, most people don't know much about the "hundred leggers." The house centipede sometimes startles people by showing up in bathtubs or sinks, but this is only one of an estimated 8,000 species in the Class Chilopoda. Want to learn more about them? Here are 10 cool facts about centipedes.
1. Centipedes are the only arthropods known to have "poison claws" for subduing prey.
The legs of the centipede's first segment are not for walking. Instead, they're modified to form venomous fangs, which they use to inject paralyzing venom into prey. These special appendages are known as forcipules, and are unique to centipedes.
2. Centipedes do not have 100 legs.
Though their common name means "one hundred legs," centipedes can have significantly less or more than 100 legs. Depending on the species, a centipede can have as few as 15 pairs of legs, or as many as 171 pairs. Regardless of the species, centipedes always have an odd number of leg pairs, so they never have exactly 100 legs (because 50 pairs is an even number).
3. Centipedes have one pair of legs per body segment.
This is the easiest way to differentiate centipedes and millipedes. Millipedes have two pairs of legs on most body segments, but centipedes always have a single pair of legs per segment. Not sure what you've found? Just count how many pairs of legs on a segment.
4. All centipedes are predators.
Though some will occasionally scavenge a meal, centipedes are primarily hunters. Smaller centipedes will catch other invertebrates, including insects, mollusks, annelids, and even other centipedes. The larger species, which inhabit the tropics, can consume frogs or even small birds. The centipede will usually wrap itself around the prey and wait for the venom to take effect before consuming the meal.
5. Centipedes can live for several years.
Compared to most arthropods, centipedes are relatively long-lived critters. It's not unusual for a centipede to live 2-3 years, and some survive longer than 5 years. Centipedes continue to molt and grow as adults, unlike insects, which complete their growth when they reach adulthood.
6. Centipedes can regenerate lost legs.
Should a centipede find itself in the grip of a bird or other predator, it can often escape by sacrificing a few legs. The bird is left with a beak full of legs, and the clever centipede makes a fast escape on those that remain. Since centipedes continue to molt as adults, they can usually repair the damage by simply regenerating legs. If you find a centipede with a few legs that are shorter than the others, it's likely in the process of recovering from a predator attack.
7. Some centipedes care for their young.
You probably wouldn't expect a centipede to be a good mother, but a surprising number of them dote on their offspring. Female soil centipedes (order Geophilomorpha) and tropical centipedes (order Scolopendromorpha) lay an egg mass in underground an burrow. The mother wraps her body around the eggs, and remains with them until they hatch, protecting them from harm.
8. Most centipedes are built for speed.
With the exception of the slow-moving soil centipedes, which are built to burrow, Chilopods can run fast! A centipede's body is suspended between in a cradle of long legs. When those legs start moving, this gives the centipede more maneuverability over and around obstacles, as it flees predators or chases prey. The tergites – the dorsal surface of the body segments – may also be modified to keep the body from swaying while in motion.
9. Some centipedes add leg pairs as they develop.
Though many centipedes hatch from their eggs with a full complement of leg pairs, certain kinds of Chilopods start life with less legs than their parents. Stone centipedes (order Lithobiomorpha) and house centipedes (order Scutigeromorpha) start out with as as few as 14 legs, but add pairs with each successive molt until they reach adulthood.
10. Centipedes are prone to dehydration.
Arthropods often have a waxy coating on the cuticle to help prevent water loss, but centipedes lack this waterproofing. Most centipedes live in moist environments, like under leaf litter or in damp, rotting wood. Those that inhabit deserts or other arid environments will often modify their behavior to minimize the risk of dehydration. They may delay activity until seasonal rains arrive, or when the humidity rises, for example, and diapause during the hottest, driest spells.
- The Myriapoda (Millipedes, Centipedes) Featuring the North American Fauna, accessed April 9, 2012
- The Earth Life Web, Centipede: Chilopoda, accessed April 9, 2012
- Soil Bugs - An illustrated guide to New Zealand soil invertebrates, accessed April 9, 2012
- The Biology of Centipedes, J.G.E. Lewis, Cambridge University Press, 2007
- Encyclopedia of Insects, 2nd Edition, edited by Vincent H. Resh and Ring T. Carde, Academic Press, 2009