I would guess some kind of Chironomid larvae, like bloodworm, in which case: Free live food
Bloodworm (Chironomid) larvae for me as well.Hi, it looks like a bloodworm, chironomid larva, good food if you can get it
They are "non-biting midges", so the females can fly. They are pretty much universal in freshwater.How could it have ended up in my aquarium though?