Very clean & crisp photo, highlighting the wonderful colouration of the subject. A common fault in zoo squirrel photography is including substrate with food remains - husks, shells & general substrate- and also, of course the wire mesh.You have done exactly the opposite, selecting a pure portrait shot.It has all come together, resulting in an optimal squirrel depiction.This quality is much rarer than one might think in squirrel photography - many people tend not to make 100% efforts when photographing thes animals.Well done!