Their fur is coarse and mostly brown with scattered black on the upper surfaces. The underside is typically grey to yellowish-white. Rats will eat nearly any type of food, but they prefer high-quality foods such as meat and fresh grain. Rats have keen taste, hearing and sense of smell. Rats have litters of 6 to 12 young, which are born 21 to 23 days after mating.
Young rats reach reproductive maturity in about three months.
Breeding is most active in spring and fall. The average female has four to six litters per year. Rats can live for up to 18 months, but most die before they are one year old. Rat Prevention and Control Sanitation. Poor sanitation and the presence of garbage help rats to survive in residential areas.