If an opossum has fallen into a garbage can, turn the pail on its side and the animal will leave after dark. Breeding season is May and June, during which time ammonia should not be used. The opossum is not aggressive, in spite of its display of sharp teeth to discourage predators. When cornered or frightened, it may play dead until the danger passes. The young are weaned in four to six weeks.
Squirrels gain access to roofs by climbing nearby trees, powerlines or trellises.
Trim back branches that overhang roofs. These procedures identify what is attracting the animal and how to remove the attraction or block access to it. When ammonia is recommended, do not use it during the breeding season. Spread baking flour in front of the den entrance at dusk and monitor for paw prints. When the animal has left, place an ammonia-soaked rag in the den and fill it in, leaving additional soaked rags along the outside perimeter of the site.