Backswimmer

When catching frog eggs and tadpoles I managed to scoop up some of these. Until I did some research I had no idea that they actually swim upside down. Every once in a while it would flip over and play dead. Unfortunately these fascinating creatures appear to be decimating my tadpole experiment. According to this website [link] they feed on small crustaceans, insect larvae, snails, and sometimes on small fish and tadpoles from which they suck the body juices. Their bite is said to be painful to humans as well.

The left side is how they swim and the right side is how they play dead.