With care, rats can live as long as four years, but on average they usually live two to three years. So it is best to get a young rat - four to six weeks is ideal.
Buying your rat young will also enable you to tame it. As rats are sociable it is ideal to keep two at a time. Make sure they are both the same sex if you don't want them to breed (see opposite section on breeding rats).

Only purchase your rats from a good breeder or reputable pet shop, where they have been kept in clean housing and not in overcrowded conditions. Do not accept a rat that shows any signs of poor condition or ill health. Healthy rats are alert and inquisitive, with bright eyes and a clean nose. Their fur should be sleek and glossy with no bald patches. The tail should also be complete with no signs of wounds or infection. The anus should be clean with no signs of staining from diarrhoea. In addition rats should move easily and not hunched up with their fur standing on end. Rats' teeth should also just touch at the tips. Make sure the breeder shows your their teeth as those that do not meet and wear against each other may cause eating problems as your rat grown older. Also check that your rat is not showing signs of breathing difficulties, such as wheezing.

Rats can have large litters (eight on average but sometimes more) and, if the male and female are kept permanently together, can produce a litter every three weeks for about six months. Easily producing over 50 offsprint! Young rats will start to breed at about nine weeks of age so additional cages will need to be provided for them from three weeks of age. If you do breed you rats please remember it is your responsibility to find the babies good homes.

Rats are sociable animals and ideally two young females can be kept together to keep each other company.

Pregnancy (gestation) lasts approximately 21 days, and when born the pups are naked and blind but grow rapidly. Their eyes open at approximately 12 days of age and can be seperated from their mothers (weaned) then, but can continue to live together until they are approximately six weeks of age. They then need to be seperated into single sex groups to prevent unwanted breeding and fighting bteween males.

Rats can be sexed by looking at the difference in distance between the anus and the genitals. There is a greater distance between the anus and the penis in males that there is between the anus and genetal opening in females.

To sex your rat, hold it gently so that it is lying with its abdomen uppermost with the tail towards you. As well as the great distance between the anus and genitals in the male, the testes within the scrotal sac should be easily visible in the adult male just above the base of the tail.