Tree hollows in old oaks or other trees and rock crevices are preferred by raccoons as sleeping, winter and litter dens, says Wikipedia. If such dens are unavailable or inconvenient, raccoons use burrows dug by other mammals, dense undergrowth or tree crotches.
Opossums are usually solitary and nomadic, staying in one area as long as food and water are easily available. Some families will group together in ready-made burrows or even under houses. Though they will temporarily occupy abandoned burrows, they do not dig their own. As nocturnal animals, they favor dark, secure areas. These areas may be below ground or above.
Raccoons are noted for their intelligence, with studies showing that they are able to remember the solution to tasks up to three years later. The diet of the omnivorous raccoon, which is usually nocturnal, consists of about 40% invertebrates, 33% plant foods, and 27% vertebrates.