The Common, Brown or Norway Rat, also known as the sewer rat, and are prevalent across the whole of the UK.
The Brown Rat is the larger of the species in the UK, often weighing over half a kilo and measuring about 23cm, without counting the tail. It has a blunt muzzle, small hair-covered ears and a tail that is shorter than its body. Colour varies from brown to black but this species is distinguished from the true Black Rat by its larger size, and its tail being shorter than its body length.
Brown Rats have well developed senses of smell taste and touch. They have an acute sense of hearing, frequently using ultrasound to communicate, and are particularly sensitive to any sudden
noise. Both species breed rapidly and become sexually mature in about three months. Each female may produce from 3 to 12 litters of between six and eight young in a year. Rats need to gnaw to keep their constantly growing incisor teeth worn down. They damage woodwork,
plastic, bricks and lead pipes, and will strip insulation from electrical cables.
Brown Rats feed mostly at night and an average rat will eat 50g of food a day. Preferred foods are cereal products, although rats are omnivorous and will eat almost anything that humans eat.
Brown Rats live in any situation that provides food, water and shelter. In homes, they will live in roof spaces, wall cavities or under floorboards. In gardens, they will burrow into grassy banks or under sheds. Brown Rats are also often found living in sewer systems, and can invade a property when the sewers are in a state of dis-repair.