We have the SAME problem!!!! It's driving me nuts too! (No, pun intended!) Our next door neighbors just moved in and when they replaced the exhaust fan above the stove, 2 dead squirrels came tumbling out. Not to be gross, but he said they were in the shape of a cube burnt to a crisp. Gag. The bad thing is they can chew on wires and that can start a fire. We do not really have an attic, only a craw space. Although I have read trapping can be inhumane, my in laws have set a trap in their attic & have not only caught squirrels, but an opossum, raccoon, and even a fox!
Here's what Animal Care Services says on this topic, perhaps this will help:
First thing you want to do is determine where the Squirrel is getting in and out (the chimney is fairly obvious). If there is more than one entrance/exit, block all of them except for one easy-to-locate spot. Obtain six to twelve, one inch strips of fabric, tie them in tight knots and soak them in household ammonia. Then, wearing rubber gloves, place these in the attic, chimney, or wall where the Squirrel has been seen or heard. Next, buy cayenne pepper at 90,000 heat units which can be found at your local natural foods store, Whole Foods or Sun Harvest. Sprinkle the pepper generously in areas that the animal has been seen coming and going near the hole, on the roof, or around trees that give the animal access to the attic. Animals cannot tolerate the presence of the pepper and they will vacate the area. Note: pets and children should not have access to the pepper! Lights and loud music at night also disturbs Squirrels who sleep during these hours. Once these techniques are used for several days, tape a piece of newspaper over the hole. If it is not disturbed for several more days, you are now safe to cover the hole or cap your chimney securely, preventing Squirrels or other animals from coming back in.
Our local wildlife rescue groups are much better equipped at handling and housing wildlife than we are. That’s what they do. That’s what they specialize in. Our focus is and always has been dogs and cats.
# Wildlife Rescue and Rehabilitation can be reached at ###-###-#### or ###-###-####. They have information on more humane ways to either live with or deter wild animals without having to resort to a potentially dangerous trap.
There are several private companies in San Antonio that will trap/pickup wild animals FOR A FEE. Residents can check out the Yellow Pages under “animal rescue and removal services” or “pest control”