What kind of worms are these?1/4

[Joene Latiolais]

I was doing a partial water change yesterday and I noticed this little hair like 1/4 inch or so white worms on the glass of the aquarium. At first I thought they were hairs(my cats love to sit on top of the aquarium where the lights make it nice and warm or just to watch the movement below) but these were moving! Are they harmful? Where did they come from (It was a new tank set up around Christmas time, and just 6 adult frogs inside until school started, then only 3 frogs until the eggs hatched, then no adult frogs, just tadpoles) I haven't noticed any in the other tank (where the males are at right now, or at the school where the females are staying)I am kind of thinking that they have always been there but not so big, and the reason they are bigger now is because of the tadpole powder I am putting in that water. But I don't know for sure, anyone have any ideas? Thanks for any information you can tell me, they kind of worry me being in the tank with the tadpoles but I don't want to hurt the tadpoles or upset their environment for no reason (if they are harmless) Joene

[toxxxickitten]

When you mean "on the glass of the aquarium?" you mean in the water with the tadpoles or just dry? If you mean in the water then they are Planaria (which are harmless). They show up when you have a lot of uneaten food in your aquarium.

[Shibumi]

Sounds like free-living nematodes. I've read other threads about them. It's basically a non-parasitic roundworm. I don't think it's harmful, but nasty looking nonetheless.