Grey squirrels are distinguished from red squirrels by their grey fur, smaller ear tufts and their larger, more robust build. Grey squirrels sit with their large bushy tail arched over the back. They are 23-30cm long with a 19-25cm tail. Adult weight is 400-600g.

They are commonly seen in woodland, hedgerows, trees, and in parks and gardens.

Grey squirrels eat acorns, tree shoots, flowers, nuts, fruits, roots and cereals. They bury surplus food 2-5cm below the soil or in tree hollows. They feed at ground level.

Grey squirrels build a spherical nest (drey), 30-60cm in diameter, with an outer frame of twigs, and dry leaves and grass inside. They are active from before sunrise to after sunset. The peak of activity is in the autumn.

The average litter is 3 young, born in the spring or late summer, sometimes both. The gestation period is 42-45 days. The young are weaned after 10 weeks and are independent at 16 weeks.

Grey squirrels can live up to 9 years.