Why do beavers build dams?

Answer: Dams create deep ponds that keep beavers safe

Dams block fish from swimming upstream — Wrong. Blocking fish isn't the goal—beavers build dams to create ponds for protection and to reach stored food through winter.

Dams give beavers a good workout — Wrong. Building a dam is hard work, but beavers don't do it for exercise—they do it to survive. The pond they create gives them protection and access to food.

Dams create deep ponds that keep beavers safe ✓ — Correct! Beavers build dams to create deep ponds that protect them from predators and give them access to food. The deep water keeps the lodge entrance underwater, so predators can't get in, and it lets beavers swim to reach branches stored for winter instead of walking on land where they're vulnerable. They build with branches, mud, and stones, and the whole family keeps the dam in good repair. The wetlands they create also help many other species, which is why beavers are called a keystone species.