Don’t panic. Take some time to think and understand what exactly is going on. Look to see how many raccoons, opossums, squirrels, etc. there are and where their den is and where they got in. What hours do they keep as they go about their daily and nightly affairs? Is the animal a mother with little babies? Exclusion techniques should not be implemented until you are absolutely certain that ALL ANIMALS are out of the space to be blocked off. If young are present, please wait until they are old enough for their mother to walk them out and then secure the entry points. Otherwise, the young will starve and you will have other unpleasant problems to solve. The babies begin to go out with mom in a few to several weeks. It is never wise to use live traps—hundreds of mother wild animals are separated from their helpless young every year as a result of the use of these so-called humane devices.
If wildlife has set up housekeeping on your property check out this link: Uninvited Wildlife