Norway rats are nocturnal and usually come inside during the fall when food is scarce. They can gnaw through almost anything including plastic, lead pipes, dry wall.
They are also good climbers and very good at burrowing in and around structures. Norway rats can grow 12-18” long with a 5-8” tail.
A single rat would have approximately 50 droppings a day. They often nest in basements, garages; they can come into a home through a hole the size of a quarter. They not only cause destruction to the home, but they are serious carriers of diseases such as jaundice, cowpox fever, plague, trichinosis, and salmonellosis. Norway rats infect food and bring fleas inside with them.