Muskrats for the swamp

Seeing the swamps being updated made me think of other animals that could fit the atmosphere, and muskrats fit pretty well. They would be semi-aquatic neutral mobs that only attack if provoked, and can be bred with sea grass. Muskrats can also build dens out of local shrubs and foliage, maybe making a new block that could be used for building. These rodents could do a lot to add life to the swamp, and make the update feel a bit bigger.