[Lukeallen225]

Hi, I have a tank for shrimp and snails. Last night I switched on the lights to see hundreds of tiny fast moving worm like bugs making there way across the glass. Does anyone have an idea what they could be? Will they harm my snails and shrimp?

Thanks
Luke

 

[Preeths]

Looks like Planaria. They are harmless.
Edit: You are over feeding, so you can reduce the food and add any small fish to eat the Planaria. Male guppies or small tetra will do. remove them after the planaria are eaten.

 

[Zoidburg]

These are *NOT* planaria. Planaria grow up larger and do go after shrimp.


What you are seeing are rhabdocoela flatworms which are indeed harmless.

 

[ThatHobbitLife]

Those look like flat worms to me. Ive seen them reduced by feeding less for a week and taking care to reduce the amount of excess foods or detritus available. I do think theyre harmless to most livestock, or at least I havent heard of them causing any issues.