In the way that we address issues with these two species, they are pretty similar (although the animals themselves are quite different). These two species are both nocturnal, only seen on occasion in the mornings or evening. This doesn’t mean they cannot be seen in the day, it is just less common and not always reason for major concern.
About Skunks
More often than not, skunks are recognized by their pungent smell before they are even seen. They often use it to try and deter invaders who try to move in, such as opossums. In the winter, skunks do not truly hibernate, but just slow down and become a bit less active. They have been spending the fall months fattening up to prepare their bodies to remain active in the winter time.
Skunks often look to take refuge under your porch, shed, deck, or other low lying structures. To prevent that and to avoid the pungent smell they bring with them, evicting them and sealing these areas before winter is crucial.
Skunks are excellent diggers, and can dig underneath things that are ground level. They require underground fence structures to be effective, and blocking an animal underneath without evicting them first can lead to death and months of awful smell.
About Opossums
Opossums are the only marsupials native to North America. They do things very similar to skunks, they spend time living under porch and shed structures, both are omnivores meaning they eat both plants and meat including insects, worms, and dead animal matter.
Possums are known to be nomadic, i.e. moving from place to place. They don’t always set up a home range and live there long term, they often move from place to place. As these animals spend time in areas, they leave pheromone smells that make an area once used more susceptible to new ones moving in.
What to look for
Signs of these species hanging around the area is areas of the yard being torn up, as they search for grubs and insects to eat overnight. Sealing the area they are living underneath with specifically designed product that prevents them from digging underneath is the long term solution for these burrowing species.