There are many of these Grey Squirrels living in the local woods, and I have seen a squirrel carrying a bunch of leaves in its mouth (see photo below) which it had gathered to build a nest with. As the name suggests, the Grey Squirrel mainly has grey fur, but it can also have a reddish colour. It has a white underside and a large bushy tail from which it get its genus name from. It maybe confused with the Red Squirrel (Sciurus vulgaris), but it is smaller, has bright chestnut fur and has become the rarer species of the two.
It builds a drey (squirrel nest) in a tree, although nests in roofs in towns. The female has two litters a year, producing up to seven young on each occasion. Its favourite food is hazelnuts and acorns, but also eats unripe cones from which it extracts the seeds. Food stores are built up in the autumn so it can eat during the winter months as it does not hibernate. They can live up to 9 years.
It is found in woodland, parks and gardens. It was originally a native species of the United States, and was introduced into Britain in the late 19th century and has now replaced the native Red Squirrel throughout most of England and Wales. It is common and widespread throughout much of lowland Britain. The Grey Squirrel is considered quite a pest by many, and it can cause severe damage to trees by stripping the bark to feed off the sap beneath.