in nature, chinchillas live in social groups that look like colonies, but are properly called herds. herd sizes can have 14 members up to 100, this is both for social interaction as well as protection from predators. they can breed any time of the year. their gestation period is 111 days, longer than most rodents. they can have long pregnancies, which is why chinchillas are born fully furred and with eyes open. litters are usually small in number, usually two.