If a squirrel has taken up residence, exclusion provides the only long-term solution for deterring squirrels away from areas where they are not wanted.
Please Note: Baby squirrels are likely to be present between March and May and again in August through September. During this time, delay any exclusion attempt for 10 to 12 weeks, when the young are incapable of accompanying the mother outside.
Start by determining where the entrance hole is located. This is often best done as the squirrel comes and goes on its morning feeding trips. If you find multiple openings, permanently seal all but one. (You’ll want to dislodge the squirrel so that you can repair or close off the entrance hole(s) without trapping the animal inside.) If they live in the attic, you can usually encourage them to leave by making noise as you enter the attic during the day.
If you can’t determine whether the squirrel has exited, install a one-way door. After two or three days, if you don’t hear noises in the attic or eaves, remove the trap door and secure the opening with new wood covered with heavy gage hardware cloth (heavy half-inch wire mesh) extended six inches beyond the hole in all directions, to prevent the squirrels from chewing their way back in. Should you inadvertently block a squirrel inside, catch it in a Hav-a-hart trap and release it outdoors.
When undertaking the repairs, ensure permanent exclusion of squirrels (and other animals) by covering all vents, louvers, and chimneys with hardware cloth and by replacing all rotten wood.