A rat is around 40 cm long and weighs 300-500 g. Rats have greyish white bellies, with the rest of their bodies being brownish grey in colour. It has a hairless tail, which can be as long as half the length of its body. It has four toes in the front paws and five toes in the rear paws. A rat can drop over one hundred droppings each day, which are capsule shaped and contain hair, and can be as long as 30 mm. The rat teeth grow up 12.5 cm per year, but gnawing keeps their length constant.
The female rats give 5-8 litter per year. Each litter contains 5-15 blind young, which open eyes in 14 days. Rats have a lifespan of longer than one year.
They have strong jumping, swimming and climbing abilities. Rats burrow under buildings, litter, rubbish, and prefer ground levels. They are mostly active at night time. Rats do not like to change routes when travelling and their travel range is no more than 30m. The rat behaviour is mostly conditioned by habits. Rats eat 100gr per day.