Silverfish in bathtubs and sinks?

Question

Is it plausible to believe that silverfish enter human dwellings through the drains? Why else are they in bathtubs and sinks?

But we almost never USE this bathtub...it's not moist.

Answer 1

Most insects end up being found in bathtubs or sinks not because it is a suitable habitat for them, but because they wander into the basin, and it is too smooth and slippery for them to get out again.

They don't come up the drain, they wander the edges of tile and counter and fall into the tub and can't get out again.

Answer 2

Moose has it right. The piping under the bathtub is like the piping under any sink in the house (so look at one of them, rather than having to tear the tub apart or taking what I describe on faith): instead of going straight down and out of the house, it goes down, bends back up and then out to wherever. What happens then is you run water into the tub/sink and it goes down, but not all of it can exit as there's nothing to push it all back up to go out. The 2-4 inches of rise as it goes back up is kind of captured rather than lost and once the tub/sink is drained completely it washes back a wee bit. This creates a plug of water in the drain pipe that mostly simply keeps horrible smells from backing up the pipes from the sewage and smelling up the house. But... it also keeps most vermin from wandering up those pipes too. The don't want to go into the water (after all, they don't know it's just a couple inches of water).

Unfortunately, if you seldom use the tub/sink/toilet, you have evaporation that is not constantly overcome with running drain water. Eventually, it evaporates enough to no longer hold the vermin back. My guess is that it still has a bit of water seal and does not smell horribly just yet or you'd have mentioned that. That means the vermin mentioned can get the moisture/humidity they need from the remaining water.

Until, of course, they explore...

So make a point of killing what's there using some liquid bug killer, then run some Drano down the pipe, let it sit some and run a few minutes of water out it to try to dislodge anything that lived through all that. Then, religiously (...on Sunday) run water for 10-20 seconds out every such drain or flush any unused toilet. That will maintain the seals in most cases and vermin stop entering. (Remember, it is the lack of use that causes this problem so simulating it with the occasional running of water will solve it.)

Good luck. Hopefully they haven't begun to explore...

Answer 3

It seems to me (I'm just speculating) that they would have to crawl an awful long way to enter the house through a bathtub or sink. I'd think it more likely that they entered through a crack in a window or door, and then gravitated to a dark moist place.

Answer 4

In buildings, silverfish can only exist in sufficiently humid, crevice-rich environments.

Answer 5

That's why the are coming out of the drian in the bath... You don't use it so they can climb up through the pipes.