Zebra mussels are tiny animals that attach themselves to things in water. A female zebra mussel can produce up to 500,000 eggs at a time. These animals can cause quite a few problems in the waters they inhabit.

Below are some issues caused by zebra mussels.
They attach themselves to native mussels and smother them.
They attach themselves to boat motors and make the motors stop working.
They eat tiny food particles that native organisms usually consume.
What are two things people can do to stop the spread of zebra mussels?