I am not sure what they are called but they are black and always on the top of the water usually in bunches not just one or two. Well my question is why don't the fish ever seem to eat them? I would think they would be a pretty easy meal for a hungry fish. I wonder if they taste funky or are dangerous for them to eat.

I have also heard before if they are there then there isn't any fish nearby, is there any truth to this? They are fun to watch move across the water but what purpose do they serve?