Here are ten things you may not have known about Sciurus carolinensis.
Grey squirrels were first released in the UK in 1876 in Henbury Park, Cheshire; it was fashionable then to have exotic species on your private estate.
They will will strip bark from trees during the summer months to get at the sugary sap beneath.
They rely on scent to find the nuts and acorns they bury in the autumn; they do not remember where they stored them.
They can be right- or left-handed!
They can swim.
They can hang upside down.
They have four fingers and five toes.
They have recently taken to living and nesting in loft spaces where they chew woodwork and ceilings, strip the insulation from electrical wiring, tear up insulation to make their nest and sometimes drown in cold water tanks.
They do not hibernate over the winter, but they sleep a lot, sometimes for days if the weather is bad.
Their young are called kittens and here is a video of some squirrel kittens trying and failing to persuade their mother to feed them:
Southwick Country Park Nature Reserve 
I love squirrels
They are the cutest and most loveable of vandals; this year, in particular, there has been SO much squirrel damage in our woods.