Grey squirrels were introduced to the UK in the late 1800's by the Victorians.
Their scientific name means creature who lives in the shadow of its tail and comes from Carolina (USA).
They have 2 litters a year, one in late winter and the other in late spring/early summer.
Litter size varies from 2 - 6 kits with young leaving the nest (dray) around 2 months old. They stop suckling shortly after and becoming independent by 4 months.
The dray is built of twigs and lined with dry grass, bark, moss and feathers.
They have a varied diet, eating fungi, nuts, flowers, tree bark, birds eggs and sunflower seeds.
They can tolerate a much higher tannin level than red squirrels giving them a wider range of nuts including acorns.
Grey squirrels carry a disease called para pox, to which they are immune, but red squirrels are not.
Squirrels do not hibernate. They build a warm winter dray to hide in and come out to collect food they have hidden when the weather permits.
Red squirrels were already in decline before the introduction of greys and now black squirrels are beginning to spread in the UK.
It is illegal to re-release a captured grey squirrel back into the wild. They must be humanely dealt with by a vet.