What brown animal that chews tree trunks and build lodges in wetlands?

The animal you're describing is a beaver. Beavers are large, semi-aquatic rodents known for their brown fur, strong teeth, and remarkable ability to fell trees and build dams and lodges in wetlands. They create these structures to provide shelter and regulate water levels in their habitats. Beavers play a crucial role in their ecosystems by creating wetlands that benefit various other species.