John Ball Zoo

What Is This Strange Thing Crawling Around My House?"

“What is this?” is a very common question I hear.  As the resident entomologist (someone who studies insects) people bring me all manner of insects, spiders, and other so-called creepy crawlies to identify.  

Here’s your chance to experience what it’s like to be zoo entomologist.  Someone comes up to you and shows you a picture of something running around in their bathtub.  What is it

Answer:  A house centipede, Scutigera coleoptrata.

They look strange and otherworldly, but house centipedes are actually quite common.  Chances are that if you start moving around boxes in your basement you will uncover a couple.  I even find them at the zoo where they live in animal buildings, offices, and even in the restrooms.

House centipedes are related to the common centipedes you find outside, with one very different and striking feature.  Their long legs.  Adults have fifteen pairs of them!  With these long legs they can move pretty fast, reaching speeds of 15 inches a second running along floors or even up walls.

Besides running, the legs of a house centipede have other important functions.  They are used for protection.  Predators will attack the legs of a house centipede instead of the centipede’s body.  The legs then break off, letting the house centipede escape.  The long rear legs even look like their antenna so predators don’t know which end is the head of the house centipede.

House centipedes also use their legs when hunting.  Even though they have well developed eyes for a centipede, they use their long antennae and legs to feel for food.  Once they find something tasty they will roll it up with their legs and use a specially modified pair of front legs to inject venom into their prey.

When house centipedes hatch they only have four pairs of legs.  As they grow and molt they add pairs of legs until they have the full adult fifteen pairs.  This usually takes three years.  They can live up to seven years.

So what should you do when you find a house centipede living in your house.  Well, you should thank him and let him go.  They are too small to inject venom into people so they can’t harm you.  In addition they help control a lot of the pest insects we don’t want in our houses by eating bedbugs, spiders, termites, cockroaches, and silverfish.