How old is a rat in human years?
Childhood and puberty Compared to humans, rats have a brief, accelerated childhood. Rats develop rapidly during infancy and become sexually mature at about 6 weeks of age. Humans, on the other hand, develop slowly and don’t hit puberty until about age 12-13 years (range: 8 to 16 years). Adolescence and adulthood Rats become sexually mature at age 6 weeks, but reach social maturity several months later at about 5 to 6 months of age (Adams and Boice 1983). In adulthood, each rat month is roughly equivalent to 2.5 human years (Ruth 1935). Female rats enter menopause between ages 15 and 18 months (Durbin 1966), while humans enter menopause between 48 and 55 years (eMedicine). Life expectancy Domestic rats live about 2 to 3.5 years (Pass and Freeth 1993). In a survey of pet rat lifespans in the UK, the average lifespan was 21.6 months, and 95% percent had died by age 3 years (Clark 2004). In contrast, wild rats living in the wild tend to live for less than one year: 95% of wild rats die bef
