Dolphins surround fish by creating a mud net. In this excerpt from the BBC's One Life reportage, we can see dolphins using an ingenious technique to catch fish more easily. In shallow water, they swim in circles by wagging their tails near the sand in order to create a mud net in order to trap fish: a fishing net made of mud. Seeing this mud barrier, the fish will try to escape by jumping over directly into the jaws of the dolphins.