A skunk smell under the house usually means one of three things: a skunk is denning in the crawlspace or under a deck, a skunk sprayed nearby and the odor drifted in through the foundation vents, or an animal has died under the floor. The fix is to find the source first, get the animal out without trapping it inside, seal the opening it used, and then clean and deodorize the area. Sealing too early, or dumping chemicals into the crawlspace, usually makes the smell worse.
We get this call often across Orange County, especially in neighborhoods near canyons, creeks, greenbelts and parks. Skunks and opossums are common in suburban OC, and a raised foundation with a broken vent screen is an easy place for them to den.
What Is Causing the Smell?
Different sources smell different, and that helps narrow it down.
Sharp, musky skunk spray that comes and goes: Often a skunk living under the house or deck that sprays when startled by a dog or cat, or a skunk passing through the yard at night. The odor tends to be strongest in the evening and early morning.
Steady skunk odor that does not fade: A skunk den under the house, often with young in late spring and early summer, or a skunk that died under the floor.
Sweet, rotting smell that gets worse over several days: Almost always a dead animal. Opossums, rats and occasionally a skunk or cat crawl into crawlspaces to die. Rats that ate poison bait often die inside walls or under floors, which is one reason we rely on trapping indoors.
Musty, ammonia smell: Urine and droppings from a den that has been used for a long time, often opossums or rats.
Flies at the vents, pets fixating on one spot in the floor, or a stain on a ceiling or wall are strong signs of a dead animal.
Skunk or Opossum?
Both animals like the same dark, sheltered spaces under raised foundations, decks and sheds, and both are active mostly at night. A few clues help tell them apart.
Skunks: Look for small cone-shaped holes in the lawn where they dug for grubs, a strong musky odor near the entrance, and a burrow or worn path under a deck or stoop. Skunks tend to den at ground level and do not climb well.
Opossums: Opossums climb well and may use fences, trees and patio covers as well as crawlspaces. They do not spray, but a long-used den has a strong urine and droppings smell. Their tracks show a distinctive hand-like rear foot.
Raccoons: Occasionally a raccoon is the culprit, usually with louder noises, heavier damage to vents or screens, and droppings in one spot.
Knowing which animal it is changes the trap setup and timing, so an inspection before setting anything saves time.
What Not to Do
Do not close the vent or access door right away. If a skunk or opossum is inside, sealing it in can leave it to die under your floor, which creates a much worse odor problem. In late spring and early summer there may also be young in the den.
Do not crawl in to look. A cornered skunk will spray, and any wild mammal can bite. Skunks are one of the animals that can carry rabies in California.
Do not pour bleach, ammonia or mothballs into the crawlspace. Mothballs are a pesticide with label restrictions, and they are not registered as a skunk repellent. Strong chemicals in a closed crawlspace can also send fumes into the house.
Do not handle a dead animal with bare hands. Use gloves and a sealed bag, or have it removed professionally.
Do not trap and drive the animal somewhere else. California does not allow trapped wildlife to be relocated and released in another area. Trapped animals must be handled according to California Department of Fish and Wildlife rules, which is one reason this work is best left to a licensed professional.
How We Handle It
Every job starts with an inspection. We walk the foundation, check every vent and access door, look under decks, porches and stoops, and look for tracks, fresh digging, hair on screen edges and droppings. If it is safe, we inspect the crawlspace itself. The steps after that depend on what we find.
Live skunk or opossum: We trap and remove the animal following California Department of Fish and Wildlife regulations. Traps are checked daily. During the spring and early summer birthing season, we check for young before closing anything off so no animals are sealed in.
Dead animal: We locate it by odor and access, remove it with proper protective equipment, bag it and dispose of it according to local rules.
Sealing the entry: Once the animal is out, we close the opening with heavy galvanized mesh, replace broken foundation vent screens and secure loose access doors. Under decks and stoops we may bury a mesh skirt so animals cannot dig back under. This step is what keeps a new skunk from moving into the same spot next season.
Odor cleanup: We remove contaminated soil, nesting material and droppings where they can be reached, treat the area with a disinfectant, and apply an enzyme-based deodorizer to break down the odor. Skunk spray can linger in soil and wood, so it can take a few days to fully clear even after the source is gone.
Typical Costs
These ranges match our published Orange County price list.
Wildlife trapping: $250 to $600, depending on the animal, the number of animals and how many visits it takes.
Dead animal removal: $150 to $400, depending on access and how much cleanup is needed.
Exclusion repairs: $300 to $1,500 or more, depending on how many vents, gaps and decks need sealing.
Inspections are free, and we put the quote in writing before work begins.
Prevention Checklist
Check foundation vents twice a year and replace any torn or rusted screens with heavy mesh.
Keep the crawlspace access door latched and in good repair.
Close the space under decks, porches and sheds with buried mesh.
Do not leave pet food out at night, and use trash cans with tight lids.
Pick up fallen fruit and clean under bird feeders.
Fix lawn grub problems; skunks dig for grubs, and small holes in the lawn overnight are a sign they are visiting.
How Long Will the Smell Last?
If a skunk sprays near the house and leaves, the odor usually fades over several days, faster with fresh air. A dead animal left in place can smell for weeks depending on its size and the weather. Once the source is removed and the area deodorized, most homes clear up within a day or two, though a strong smell in wood or soil can take longer.
Get Help Today
If the smell is strong or getting worse, call early. We often trace the source the same day. Learn more about our wildlife trapping and removal in Orange County, our dead animal removal and odor cleanup, and crawlspace and foundation exclusion repairs. Opossums are the other frequent crawlspace guest; read about them on our opossum identification page.
Yogi's Pest Control is owner-operated by Yobani Arreola, licensed by the California Structural Pest Control Board (OPR 14866), and based in Tustin. We serve all of Orange County 7 days a week, 8 AM to 8 PM. Call 714-323-8262 for a free inspection.
