The grey squirrel could nest in your wall surface cavities, in between false wall surfaces and in the loft, The squirrel might consume roofing system insulation for nesting products and may munch boxes and other products kept in the roof covering room, in some circumstances they have been known to chomp electrical cables and roof joists causing a potentially unsafe condition, at the same time creating the issue of sound.
The grey squirrel is a non-native species and is not protected. In fact it is prohibited to 'live trap' a grey Squirrel and release it back into the wild.
At NLPC we just make use of 'killing catches' as a control approach. This by far the most gentle approach of control and unlike using toxins the body is always recuperated.