Good afternoon. The quick answers to your questions are: 1) they might come back, but you can take steps to keep them out of the house, and 2) yes.
See the response below provided by Scott Jacoby, Illinois Department of Natural Resources district wildlife biologist, for more details.
Raccoons can be a real problem in a home. They can cause damage getting in and then cause more damage once they’re inside. The best thing to do is to prevent them from getting in your home in the first place. Make your property as uninviting as possible for raccoons. Do not feed them. Do not approach them. Make sure they can’t get in any of your buildings to have their young or shelter from the weather. Be sure your garbage is not available to them. Do not leave pet food outside once your pets are finished eating. Clean up under bird feeders. Keep trees and other vegetation trimmed away from your buildings so they can’t use them as ladders to access your buildings. If you see them and can safely do so, spray them with a hose. That being said, once they have gotten in they need to be dealt with. First, you should hire an animal control contractor to trap the raccoons and remove them from the building. You can locate an animal control contractor using the Living With Illinois Wildlife website (http://web.extension.uiuc.edu/wildlife/). After he is satisfied that all the raccoons have been caught, he should repair the entrance they have been using so it is no longer available to raccoons. All feces and soiled insulation, drywall, and plaster should be removed. Whoever does this should wear a respirator. The area may need to be sprayed with an odor neutralizing product, but your contractor will advise you on that and any other details that will need to be addressed. Once you have excluded the animals and removed the damaged pieces of your home, you can then repair what was damaged. Good luck and remember, it’s cheaper and easier to keep them out than it is to get them out.
