University of Maryland Extension



The most common rat in Maryland is the Norway Rat, also known as the sewer, barn or wharf rat. It came to North America on ships from Europe by early settlers. The Norway Rat's color is typically brownish gray, although some may be reddish. It can grow to over a foot long including the tail and weigh over a pound. Norway rats live in close association with people, and spread filth and human sickness. They nest in burrows dug under buildings, walks, around ponds and in garbage dumps. They occasionally will burrow in back yard compost piles that contain a source of food such as table scraps. Unlike the house mouse, rats need free water for drinking. They will eat nearly any type of food including meat and fish. Rats are primarily nocturnal but when populations are high, some may be active during daylight. Rats, like mice, need to gnaw to keep their constantly growing teeth trimmed. They do considerable damage to wood, wiring, and plastic, and have been known to also chew on metal.

Control rats by cleaning up all sources of food both indoors and out. Take particular precautions to prevent them from getting into the trash and garbage set out for pick-up. Use metal cans with tight-fitting lids instead of plastic bags or cans. Set snap traps, glue boards and baits close to walls, behind objects, in dark corners and other places where they have been seen. For severe rat infestations, professional extermination should be sought.  

rat entry
They nest in burrows dug under buildings, walks compost piles, around ponds and in garbage dumps.

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