It’s about 2-3mm in length. Central European location.
It looks like a silverfish to me, but I've never seen them bigger than about 1cm.
this post was submitted on 27 May 2026
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What is this thing?
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Sorry, I made a typo. It should’ve been mm, not cm
If I’m reading this correctly, they shouldn’t be harmful to humans, right?
I’m wondering whether I should report them to someone or let them be
They don't hurt humans or pets. They'll also tend to hide, given the opportunity.
They do like to eat paper, however. One silverfish isn't a big deal, but if you see them often it's worth looking into deterrents or pest treatment. When there are lots, you'll start to notice holes in notes, books, etc — most particularly (in my experience), loose pieces of paper left undisturbed for a length of time.
I've had a few in my apartment. I sprinkled dichotomous Earth where I saw them and haven't seen any more for a while.
dichotomous Earth
Sounds like a cool book title or band name.
I think autocorrect screwed you and you meant diatomaceous?
Sounds like a cool book title or band name.
But not both!
Inclusive or
Ha, a dichotomy is XOR by definition.
Jointly exhaustive then
Maybe it's just a very tasty book and they haven't come back because they're so full.
Correct!
They are harmless per se, however if they appear suddenly they might be an indication of a water leak or humidity to which they're drawn to. They like to settle on starchy materials: books, wallpaper that sort of stuff.
Not harmful, mostly an annoyance.
It's the gray or long-tailed silverfish: https://en.wikipedia.org/wiki/Ctenolepisma_longicaudatum
They can be somewhat of a pest if they are in your house (unlike regular silverfish, who are relatively benign) and if you have books, or other papermaterial stored.
They are indeed harmless, but they can multiply a lot and ruin furniture if left undisturbed. My mom spent this winter dealing with an infestation in her house.
If you keep seeing them, you should take action before they can get out of hand
We have some that get 2-3 cm long.
This is NOT a regular silverfish but a longtailed one or paperfish (Papierfischchen when you live in Germany)
Wikipedia: https://en.wikipedia.org/wiki/Ctenolepisma_longicaudatum
They are not as useful as silverfish but not dangerous - except for your books and paperwork. We've also have them in our flat. They like it dry and feed on paper.
Silverfish have a use?
They eat mold afaik. So if you see them, you know there's a source of humidity/mold you ought to check out.
Don't they also eat all your paper and organic fabrics?
Exactly. Also silverfish eat house dust mites.
Eating books and paperwork.
They eat bugs and stuff. Not spiders though, that's a myth (unless they're already dead maybe).
Might be thinking of house centipedes which do eat spiders and are also commonly called silverfish, at least around where I'm from anyway.
Yes. Would agree that this is a paperfish. If you see them too often you realy should consider a pesticide.
Silverfish. In Italy it is said they come out from hiding before rain starts. Normally, if you see one in your house, it should mean rains are coming today or the day after.
They are harmless to us and pets.
I highly recommend submitting observations of unknown animals/plants to inaturalist.org: you can get a very reasonable software guess, informed identifications from other people (possibly those specializing in that kind of creature), and contribute to science at the same time!
Oh hell yeah, that's what I've been using Google lens for like, half the time, and I'd much rather do something like this
They have an app called Seek that I use all the time!
Stop digging too high up in the nether!
Silverfish or possibly a firebrat.
Are you sure it's not a goldfish?
Pee-hole bug
Looks like a silverfish.
https://en.wikipedia.org/wiki/Silverfish
Watch out, they will eat your books/paper products.
If that's 2-3mm then the wooden tiles must be 1-2cm wide, which doesn't sound right to me
They are. They are quite small