You'll most likely smell a skunk before seeing one. They tend to leave a slight stench in the areas they frequent during the day, even if they do not spray in your yard. If you smell skunks in the late winter, it's conceivable that neighboring males are competing for female partners.
Round, shallow holes that are completely circular are another evidence of skunks on your property. Skunks are special in that they only dig deep enough to find grubs and other insects that live in the dirt. It's possible that they'll leave tracks in the loose earth. These footsteps resemble those of a cat, however they have five toes instead of four.
Raccoons have the ability to wreak a remarkable amount of damage in a short period of time. Vent ducts, insulation, fan vents, cooling systems, insulation, and even robust wood beams can all be shredded by their razor-sharp claws and teeth. They also defecate and urinate in large quantities, usually in the same place where they have set up their "restroom." This feces and urine become lodged in the insulation and eventually soak through to the underlying wood. All of this means that your raccoon problem is unlikely to improve over time. It's only going to get worse. If a raccoon dies in your home, you'll know immediately since the smell is terrible.