Muskrat

Muskrat is a passive mob that spawns in swamps and rivers. They are often seen chomping up wood and making themselves dams. They can use abandoned beaver dams.

Spawning
Muskrats spawn in rivers, lakes, swamps, wetlands or taigas (that are near a large water source). 4% of them spawn as babies.

Behaviour
Muskrats are nocturnal animals. Muskrats automatically run towards water and start chomping up nearby wood sources and then create dams for them to live in, if a beaver dies and their dam is left in the open, muskrats can use those dams. Muskrats are afraid of players and they instantly run away. Muskrats are very social and are never usually alone, if their left alone they will try their hardest to find a muskrat group to join. Muskrats flee from foxes, minks, raccoons and wolves as they attack them.

Muskrats are very playful creatures and like to playfully chase nearby ducks around, but not to cause harm. When a muskrat breeds they usually have around 6-8 infants.