what are water fleas?
<answer> The water flea is a microscopic crustacean that lives in lakes, ponds, swamps, and streams. <context> Many water fleas swimming together. The water flea is a microscopic crustacean (around .2-5 mm long) that lives in lakes, ponds, swamps, and streams. The most common kind of water flea is the Daphnia. This little, translucent insect is named for the way it swims.