This little Red Squirrel lives in the British Wildlife Centre, Surrey in a specially created walk through enclosure. It is not so much of keeping them in, but to keep the Grey Squirrel out.
Red Squirrels have become an endangered specie in the UK, due to the importation of the North American grey squirrel. The grey squirrel is larger in size and carries diseases to which the red squirrel is not immune too.
Unlike the grey squirrel these little darlings move like grease lightening through the trees. They are also monogamous and stay with their mate for life. If one of the pair dies, usually the other one dies too of grief
This image was taken at the BWC, not caged