In late winter, squirrels may be seen courting, one, or more, chattering males chasing a female through the tree or across the ground. Females can mate only twice a year, but males may mate at any time. After mating, the male plays no part in the rearing of his young.
The female uses a winter drey as a maternity nest, or builds a new one. She lines it with soft material and gives birth after a six week gestation period (time between mating and birth), in March/April and perhaps again in June/July.
An average litter has 3 babies but as many as 9 may be born. The mother suckles the naked, blind young every three or four hours for several weeks. They gradually grow fur, their eyes open and at about seven weeks old they follow their mother out on to the branches. Gradually they start to eat solid food and when their teeth are fully grown, at 10 weeks, they give up suckling. A month or so later they move away from the nest to build dreys of their own. If there are not too many squirrels in the area, the young stay nearby; if it is crowded they will be chased away to look for less crowded feeding areas.
Grey squirrels breed for the first time at a year old.Read More: Grey Squirrels and humans