Rodent Life Cycle
Rats and mice have incredible reproductive capabilities. Mice have a quick maturation process and reach sexual maturity at 4-8 weeks of age. The gestation period of mice is a short period of about three weeks and one rodent can give birth to 5 or 6 babies.
Norway and roof rats become sexually mature and able to mate at 8 to 12 weeks of age. They also have a gestation period of about 3 weeks. Norway rats can have an average of 8 – 12 pups per litter while roof rats have 4 to 8 pups per litter. It’s not uncommon for rats to have five to ten litters per year.
Mice can give birth in as little as 25 days after the first litter. Female mice can be in heat and become pregnant in 24 to 48 hours after giving birth to their offspring.
The standard life expectancy of mice and rats is about one year. However, indoor rodents can live for 2 to 3 years. Without harsh environments or predators such as owls, cats, or hawks, rodents can be expected to live longer.
Mice and rats that live indoors with adequate food, water and shelter can have increased capacity to breed all year long. The winter months may be too cold to allow for successful reproduction so rodents living outdoors may only be able to breed during the spring, summer and fall. A rodent can continue this breeding lifecycle until it dies. Once you come to terms with the multiplication rate of these animals, you’ll realize how quickly a mice control issue may get out of hand by the end of the year. You may have more rats than you bargained for unless you tackle the issue as soon as possible.