What is this??

[Godwin827]

I was trying to breed bettas and after the female was removed I see these small creatures squirming in the tank. They do not look like baby fry. Any one can help me what these are. I included pic

 

[Sgooosh]

I was trying to breed bettas and after the female was removed I see these small creatures squirming in the tank. They do not look like baby fry. Any one can help me what these are. I included pic View attachment 140881

could you upload a video?
is it a poop?
mosquito larva?

 

[PheonixKingZ]

Very hard to see. More pictures please?

 

[WhistlingBadger]

Yep, we'd need a better pic, or at least a description of how it's moving. Could be a detritus worm; could be a hydra; could be fry; could be fish poop...