Content Update: October 6, 2025

Learn more about how rats live, reproduce, and die.

Key takeaways

  • The Norway rat and the roof rat are the two most common species of rat in the United States, and they both have very similar life cycles.
  • Rats are highly social animals, and they live in nests consisting of an alpha male and multiple female and young rats.
  • Rats can have up to five litters per year, and they have relatively short gestation periods, only taking around 21 days for most species.
  • On average, a rat in the wild will live for around one to two years. Females typically outlive males.

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Though there are a wide variety of rats that can be found in the United States, the two most common are the Norway rat and the roof rat. Both of these species of rat are most often found around populated areas, and are sometimes referred to as “Old World” rats due to their origins stemming from being transported to North America via ships from Europe. Despite having a few behavioural differences, the overall life cycle for both species is similar—and here’s what you should know about how these rats live.

Where and how do rats nest?

Rats are social animals. Most species of rats live in nests comprised of an alpha male, several females, and the young rats. The dominant male watches out for the family and prevents other males from mating with his group of females.

Many rat families have multiple nest sites and move between them depending on the availability of food and water. Depending on the type of rat, nest sites are located at either a high or low elevation. Roof rats seek out locations in trees, shrubbery, attics or crawl spaces, while Norway rats are more likely to be found on the ground floor or below ground.

These rodents normally travel up to 300 feet from the nest in search of food and water and to patrol their territory. However, if food and water dry up, they will venture much farther to get what they need.

rats nest

How fast do rats reproduce?

Under ideal conditions, a female rat can have up to five litters per year, and each litter will consist of around 6-10 pups. Young rats are born blind, deaf, and without fur, and are weaned about three weeks after birth before reaching sexual maturity at around three months.

The gestation period for rats is quite short, averaging around three weeks for most species. Though rats tend to mate close to where they were born, they’ll still move to new territory if the space is too crowded.

How long do rats live?

The average rat in the wild will live for around one to two years, with female rats typically outliving the males. Compared to pet rats, wild rats face significantly more survival challenges, including:

  • Predation: Many animals feed on rats, including cats, birds of prey, snakes, and more.
  • Pest control: Traps, baits, and other forms of rat control levied against rats have a major impact on their survival.
  • Vehicles: Being hit by a car, truck, or another kind of vehicle is a common cause of death for rats.

If you suspect you have rats in or near your home, it’s best to call a pest management professional. Controlling a rat population requires a multi-step approach, and Terminix Service Technicians are trained to know what methods will work best in your home. Call today for a free pest estimate.