Skunks are ground-dwelling animals that dig burrows under decks, sheds, porches, and foundations, often widening an existing gap rather than starting from scratch. They are generally not aggressive, but will spray a strong, long-lasting odour if startled or cornered, which is usually what prompts a call for help.
Signs of skunk activity include small, cone-shaped digging in lawns as they search for grubs, and a musky smell near a den entrance. Skirting decks and sheds with mesh buried below ground level prevents skunks from establishing a den underneath in the first place.