They have sharp, curved claws for climbing trees, and strong hind legs enabling them to leap from branch to branch and they are even able to swim short distances, although this behaviour is rarely observed.

They shed their coats twice per year, switching from a thicker winter coat to a thinner summer coat. During the summer months their coats are a uniform reddish brown with creamy white underparts. In the winter their coats are thicker; the back portion of the body commonly turns a greyish brown colour, while the legs and head remain reddish brown.

Red Squirrels are typically solitary although neighbouring territories sometimes overlap, and during the winter months several Red Squirrels may share a drey in order to keep warm.

They can be found in coniferous trees and broadleaved woodland, feeding on a variety of different material: nuts extracted from pinecones, hazelnuts, beech nuts, chestnuts, acorns, berries, buds, shoots, some species of fungi, insects, and occasionally birds' eggs.

Excess food is stored in nooks or holes in trees, or buried underground to be eaten when food is scarce. The majority of feeding activity takes place in the early morning and late afternoon. Red Squirrels typically spend the rest of their day resting in their drey.

Dreys are constructed from twigs lined with moss and grass. Red Squirrels tend to construct dreys in branch forks (although tree hollows and woodpecker holes are also sometimes used) close to the trunks of trees, approximately 10-15m above the ground.