The animal will need to be trapped and any openings under the porch will need to be sealed off. Homeowners are allowed to trap nuisance wildlife themselves if they have a permit from the Illinois Department of Natural Resources. But a bobcat is best handled by a professional. I'd strongly suggest that you hire a nuisance wildlife control operator. You can find NWCOs in your area at:
http://web.extension.illinois.edu/wildlife/professionals.cfm Bobcats are in the peak of their breeding season in February and March (gestation is only 60 days). Have the NWCO check to make sure there aren't kittens under the porch before it gets sealed up. Otherwise, if the bobcat is released back onto the property rather than being euthanized, she'll just dig her way back in to get to the young. If you need more information you can contact the IDNR district wildlife biologist for advice: Mike Chandler at (309) 543-3288
