Norway rats, also known as common, or brown rats, have black-speckled brown fur, and a slightly lighter underside. They’re generally fewer than ten inches long, occasionally reaching 9.5 inches. They have 4 legs, small black eyes, and their tails are not very long relative to the size of other rodent tails.
Norway rats generally live outside, but they’ll enter your home in the autumn when food sources are harder to come by. They’re voracious animals, and have been known to chew through plastic and metal just to get to a food source. Norway rats are concerning to humans because of the structural damage that they can cause to a home, as well as the diseases that they carry. They’re vectors of trichinosis, jaundice, plague, and rat-bite fever among others. Check your home for signs of norway rats, such as droppings, oily trails along walls, and chew marks. Keep all holes and cracks in your home sealed so that rats cannot enter, and be especially diligent about this towards the end of summer.