How big do rats get?

Rats are breed of mouse-like rodents that grow over 4,5 inches and weight over 1 pound. There is over 50 different subspecies of rats that live all around the world. Two most well-known species are black rat (Rattus rattus) and dark/Norwegian rat (Rattus norvegicus). Rats live near human settlements or even in human homes due to the abundance of food resources. Damage that rats cause are primary reason why rats are called vermin and why people go to wide lengths to remove them. Rats are hygienic problem of human kind, especially in large cities. Besides generally negative opinion about them, there are lots of people who keep rats as pets.



Rat's body length is approximately from 15 to 18.5 inches, including tail. Body mass of adult female is from 14.10 oz to 17.60 oz, while adult male rat weights from 17.60 oz to 24.70 oz. Of course, there are some much larger subspecies, so we must mention Gambian pouched rat, which is the largest recorded rat species. Gambian pouched rat can reach up to 3 feet in length and weight up to 5 pounds, although there were some examples that weighted almost 9 pounds.

When they are born, rats weight 0.15 oz and after just 100 days, their weight increases more than 40 times and young rats weight approximately 8.80 oz. Rats start getting body hair 2-3 days after they are born and their front teeth appear about a week later, just as excellent swimming ability. Rats open their eyes 10-17 days after they are born. Body temperature of an adult rat ranges from 37.5 to 38.8 Degrees Celsius.

Female rat is fertile 3 months after birth and male in 4 months. Number of broods is 8-9 a year and number of babies in a single brood can reach 23 (on average 9-12). Female's pregnancy lasts 3 weeks and breastfeeding lasts for 28 days. If breastfeeding female rat dies for any reason, her sister will take care for her brood and continue breastfeeding them. In theory, one couple can create up to 15.000 rats a year! Rat's teeth grow up to 5,5 inches a year which is the reason why rats have such a strong need to mill-to use them. Rats can go over 40 miles in a week, in a search for food, and can jump up to 3 feet high from spot. Rats live in communities, create packs and are generally nocturnal animals. Rat's average lifespan is 3-7 years.

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