What could this be?

[Mujtaba]

When I 5x zoom in my small pond, I see this small critters they are everywhere and I think they are munching on dead leaves and stuff. What can they be and will they harm my fish in it? You will have to zoom the pic to see them in bunch near a dead leaf.

 

[Andy Sager]

Check this out and see if this fits your "worm" Amphibious caterpillars discovered in Hawaii (w/ Video)

 

[Mujtaba]

Check this out and see if this fits your "worm" Amphibious caterpillars discovered in Hawaii (w/ Video)

No this worms are different.

 

[Andy Sager]

No this worms are different.

It was worth a shot. I have no idea then. I would harvest them, place them in a tank or container with some leaves they were eating and a screen lid and see if they turn into something terrestrial or aerial. When the ponds are outside, you can get anything in there.