Why Do Pets Live Such Short Lives. Hamsters can reach sexual maturity as young as 1 month old and can give birth multiple times a year, each time possibly bearing multiple young. Scientists worked out a long time ago that the lifespan of animals is mostly related to their size.
A hamster’s heart beats at the rate of 500 times every minute. Bigger animals usually live longer than smaller. Animals play an important role in many people’s lives.