Animal traps or live traps for squirrels are the best way to remove animal from attic without calling a professional animal control service. Squirrels are very smart and will leave their food, water, and nesting boxes alone, but if you have a raccoon or other large rodent population in your attic, they will often seek out food, water, or new places to build their nests. In addition, they will tear down attic insulation and leave small holes or chew holes in the sheetrock. Raccoons can even get into attics where there is wiring or electrical work.
If you have raccoons, mice, or other rodents creating havoc in your house, you need to get rid of them before they get too big. You may want to call a professional wildlife removal company right away because grey squirrels are very crafty when it comes to hiding and moving around an attic.