Rats and muskrats have some similar features, but there are a number of distinct traits that each possess that make it easy to differentiate between the species. Although both muskrats and rats are rodents, their habitats, social structures and overall appearances differ significantly.
Rats are land dwellers where muskrats are more aquatic. Rats will burrow on land or create a habitat near humans, living in attics, walls, basements and ceilings. Rats will also live in trees, and enter your home through holes in the attic or roof, where they can build burrows. Rats coexist with humans, getting food, water and shelter easily from various sources they scavenge. Rats will also breed profusely and can create enough offspring in your home to cause an infestation is a relatively short time.
Muskrats dwell near water, making their homes on riverbanks or lakeshores and stay clear of humans. They are much more solitary in natures, whereas rats live together in groups within their burrows. Muskrats also can survive underwater, which rats cannot. However, Norway rats are very good swimmers.
The body of a rat and a muskrat are similar. Both have brown or dark fur and long tails. A muskrat tail is wider than a rat tail. The fur on a rat is often much dirtier and oilier than a muskrat coat. A rat's fur will often leave a coating of oil and dirt along pathways that they travel, called a smudge. Muskrat fur is dense and also waterproof.
Muskrats are known for their distinct, musky odor that they will emit when they or their territory are threatened. Rats lack any forms of defense similar to those of the muskrat. They rely on their speed and their sharp teeth and claws to fight off any predators.