Originally introduced from North America, grey squirrels are now common in England, Wales and central Scotland.
Where grey squirrels live
They mostly live in broadleaf woodlands containing oak, beech, sweet chestnut and hazel but will also be found in a wide range of habitats such as parks, gardens and urban areas where there are suitable trees.
What grey squirrels eat
Grey squirrels mainly eat seeds and plants buds, shoots, fungi and flowers but will also eat insects, birds' eggs, and will take food from bird feeders in gardens.
Squirrels will retrieve nuts they've buried mainly by a sense of smell, but will also have some form of a mental map of locations. However, many of the nuts and seeds buried are not rediscovered which helps the growth of new plants.
When grey squirrels are born
Usually, squirrels will have two litters of young a year - one between February and March and the other between June and July. Litter size averages three to four babies.
Age they leave the nest
Baby squirrels eyes open at four weeks and they start to explore outside the nest at about six weeks old. They're weaned by ten weeks and then quickly become independent at around 10-12 weeks.
Squirrels make a spherical nest out of twigs and leaves, typically found in the forks between branches at least 6 meters off the ground. They'll also use tree cavities and occasionally nest inside roof cavities.
The difference between red and grey squirrels
How to tell them apart and what to look out for.
Coat colour isn't an easy way to differentiate between red and grey squirrels.
Grey squirrel colours can vary from grey to black, but they can also have red-tipped coats. A red squirrel coat colour can vary from the classic rusty red to much darker colours like grey and black. Therefore, their coat colours can look very similar.
Red squirrels have ear tufts whereas grey squirrels don't. However, reds will moult these tufts in the summer.
Red squirrels are much smaller than greys, but a young grey squirrel may be a similar size to an adult red squirrel.
One reliable way to distinguish between the two species is tail colouration. The hairs on grey squirrel tails have bands of colour, each having a white tip. Red squirrel tails can vary in colour but their tail hairs don't have these bands.
Grey squirrels can't be released back into the wild
A new law 'The Invasive Alien Species (Enforcement and Permitting) Order 2019' means that it's no longer possible to rehabilitate and release grey squirrels.