A reader sent us a question about three-inch brown worms that he is finding on his kitchen floor, as well as occasionally in his living room and bathroom. The worms (if they even are worms – they might be centipedes) move “very fast like a snake.” In fact, even when they aren’t moving quickly, the way they move still resembles a snake. So we are dealing with brown worms (or “brownish” worms, as the reader has it) that are three inches long and move like snakes, often quite quickly. To this description the reader adds two notes: first, he only finds the worms or centipedes or whatever they are one at a time. Second, and rather gruesomely, the creatures only die when they are burned in a fire. (Unfortunately, one is all but forced to imagine the other methods that failed.) In light of all this information, what is our reader finding?

Having a picture is always helpful, but it would be especially helpful in this instance because, as we indicated above, we suspect our reader is finding centipedes. A reasonably clear photo of one of the creatures could easily establish this. If it has lots of legs, and there is one pair per body segment, then he found centipedes. However, even without a picture we are pretty sure this is what he is finding, primarily because of the way he describes their movement. Although some centipedes are too short for their bodies to noticeably undulate while they move, one that is three inches long could certainly wiggle its body a little bit, making its movement snake-like.

The fact that the creature can move quickly also suggests that our reader is finding centipedes, which are very fast. Their undulating bodies are partially responsible for this, but so are their legs, which grow longer the further back they are on the centipede’s body. Because of this, their legs are allowed greater movement because one pair of legs isn’t limited by the pair in front of it. The fact that what our reader found is fast also rules out two other possibilities that we briefly considered: millipedes and earthworms. Although millipedes can curve their bodies in a way reminiscent of snakes, they are actually very slow. (Their way of movement – with their legs all working in wave-like sync – is good for burrowing, but not getting around quickly.) Earthworms can also slither along in a way vaguely like snakes, but they are also extremely slow, and we only thought of them because our reader described his find as three inches long and brown, which fits the description of an earthworm.

One limitation of the centipede hypothesis is that the reader didn’t mention that the creature he found had any legs, and the legs on a centipede are quite noticeable because they extend out from the body. However, given that the creature crawls quickly, as opposed to inches along the ground, we think a centipede is the most reasonable possibility to put forward.

Finally, the reader did express interest in getting rid of the centipedes (if that’s what they are), but all we can say on this front is quite straightforward: he should make sure that there aren’t any obvious ways for the creatures to get into his house. Unfortunately, insects and other creatures will almost always find a way into a house, but the problem can be reduced if at least large cracks or other openings (e.g., a gap under a door) are sealed, just as flies tend not to get into your house when you don’t have an open window with no screen. Also, we should mention that it doesn’t seem like our reader is dealing with a particularly bad problem. As he himself noted, he only ever finds one at a time, so he likely isn’t dealing with an infestation. And regardless of how many he is finding, it seems a bit harsh to burn them in a fire. We’re not sure if a centipede enjoys any faint glimmering of a mental life (they are at least self-directing, after all) or if their nervous system is capable of experiencing pain, but it still strikes us as unnecessary to burn them.

We wish our reader the best of luck in dealing with his problem, and encourage him to further research centipedes to see if our suggestion is correct.