Book 30, Question 67
What lives in the mud at the bottom of a lake?
The bottom of a lake is full of life.
Midge larvae, some red like tiny worms, build tubes in the mud. Clams filter water, and tiny worms eat bits of dead plants. Snails graze on algae. These bottom-dwellers break down waste and feed fish like perch. Scientists sample the bottom with scoops to see how healthy a lake is.