Little black worms in a toilet, what could they be? Where did they come from?

-So there's this one toilet in the house that we don't use cause it doesn't flush and we didn't fix it yet. Problems with pipes or something.



I never use that toilet, but the other day I stopped home to get some stuff and two friends were with me, one asked to use the toilet and I said I'd show him to a working one. The other didn't realize there was a problem and she went and used it anyway and complained she couldn't flush. So later I went to find a way to flush and I notice tons of tiny black worms or larvae or whatever. Now at first I thought it was pubic hair or something, had no idea what to think. But then I realize they move around. It's the only place with a problem. Other toilets are fine.



I searched YA! but all the questions had 1 inch worms or half inch, these were tiny like 0.04 of an inch lol!

and looked black like tiny lines, threads...



What could they be and where did they come from? It's so gross lol and I really hope the girl didn't see them, it's embarrassing enough that she used a toilet that didn't work and was dirty cause no one uses it and no toilet paper! Ahh! haha!Some kind of insect larvae, like from mosquitoes. They will lay eggs in any water that doesn't move.That's fuc*ing gross lol I say take out the damn toilet and replace it before those worms begin to grow lol or what if some other type of insect feels like moving in haha sick!!!
They probably got pooped. They came from inside