Yes, a loud air horn will usually send a skunk or opossum out from under your deck or shed. But a horn is only one step in an eviction, and if you blast at the wrong moment from the wrong spot you can end up sprayed or with an opossum playing dead in the middle of your crawl space.
The short answer: noise starts the eviction, exclusion finishes it
Skunks and opossums move in under decks, porches, and sheds because the space is dark, dry, and quiet. Take away the quiet and it stops being a good den. Washington's wildlife agency (WDFW) says the same thing in its guide to evicting animals from buildings: make the den uncomfortable with bright light and a radio playing loud, let the animal leave on its own, then seal the entry. A battery train horn is just a much stronger version of that "harass" step.
The same guide gives two reasons for patience:
- Skunks move around a lot. WDFW notes that a skunk usually uses a den for only two or three nights in a row. Females stay longer in mating and nesting season.
- Ultrasonic gadgets don't count. WDFW says there is no scientific evidence that commercial ultrasonic devices drive animals out of buildings. Animals get used to them, and the sound fades quickly with distance and doesn't get past obstacles.
So the horn doesn't repel anything permanently. It's a strong signal that the den is no longer safe. If you don't block the hole after the animal leaves, the scent trail will bring the next skunk or opossum right back.
Skunks vs. opossums: why they react differently to a blast
These two animals often use the same type of den, but a sudden loud noise affects them in different ways. That changes how you use the horn on each one.
| Striped skunk | Virginia opossum | |
|---|---|---|
| Typical first reaction to a threat | Stomps its front feet, makes short charges with the tail raised, then turns its rear toward you and sprays (WDFW) | Hisses with its mouth open (a bluff), bares its 50 teeth, or "plays dead" |
| Defensive range | Accurate to about 12 ft on a still day, 18 ft or more in wind (WDFW) | Hissing is a bluff. Long Beach Animal Care Services calls it "merely a bluff to look vicious" |
| Young in the den | Born late April through May. The mother leads them out at about 60 days | Carried in the pouch for almost 70 days, weaned at about 100 days (Georgia DNR) |
| Rabies concern | Skunks account for 17% of U.S. rabies exposures from wildlife, per the CDC | Georgia DNR calls rabies in opossums "exceedingly rare" |
In practice: a skunk is likely to leave if you scare it from a distance, but it sprays if it feels cornered. An opossum may not run at all. It can freeze or "play possum," an involuntary shock reaction. If an opossum goes limp after a blast, stop. Go back inside, give it a couple of hours, and it will wake up and leave quietly.
The no-spray setup: put distance and a remote between you and the hole
Most people who get sprayed by a skunk under a deck were standing right at the hole, holding the horn, when the animal came out. A wireless remote fixes that. Set the horn down, walk away, and trigger it from a place the skunk can't reach.
- Stage the horn 15 to 20 feet from the entry, off to one side. Never put it in the exit path. A skunk leaving the den will head straight along its usual route, and you don't want the horn or yourself on that route.
- Aim the trumpets across the opening, not into it. At close range, the goal is to make the den feel unsafe. You're not trying to blast a trapped animal point-blank.
- Trigger from indoors or from well beyond 20 feet. That's past WDFW's windy-day spray distance. A standard remote covers this easily, and a long-range remote lets you fire from across the property.
- Use short blasts at irregular intervals. One or two half-second blasts at dusk, then nothing, then another blast later. Unpredictable noise is harder for an animal to get used to than a steady sound.
Any horn in our wireless-remote line works this way. You don't need 150 dB to bother an animal 20 feet away, but the remote matters a lot.
If you already run cordless tools, the Extreme Series Train Horn for Milwaukee® 18v Battery clips onto any M18™ pack, puts out 150 dB, and ships with a wireless remote rated to 160 feet. You can upgrade to a long-range remote that reaches up to 2,000 feet. The same horn that clears out a skunk will also cover coyotes, hogs, or stray dogs at the back of the property. Dual-trumpet models are a good lower-cost choice if you only need it for the yard. For every tier and battery platform side by side, see our train horn buyer's guide.
Step-by-step: getting them out from under a deck or shed
This sequence follows the WDFW eviction guide and the Minnesota DNR skunk guidance. The horn is used in step 4.
- 1. Find every opening. Walk the skirting, lattice, and foundation with a flashlight. Seal every gap except the main, active one. If you leave a back door open, the animal will just move deeper under the structure.
- 2. Confirm the hole is in use. Loosely stuff it with wadded newspaper, or spread a tracking patch of baby powder or fine sand about two feet around it. WDFW advises against flour because it can attract a hungry animal. Look for disturbance or tracks after dark.
- 3. Check for young (see the next section). If babies may be inside, stop here and change your plan.
- 4. Harass at dusk. Put a bright work light under the deck, and use the remote to give the horn a few short blasts around dusk, when skunks and opossums normally head out to feed. Repeat for a few evenings.
- 5. Verify they're gone. WDFW's rule: if the loose newspaper plug stays untouched for three days of fair weather, the animals have left. Another option is a one-way door left in place for about seven days.
- 6. Seal it for good. Minnesota DNR recommends burying heavy-gauge galvanized hardware cloth at least 12 inches deep around entrances and bending it outward at least 12 inches, so a digging skunk hits the mesh instead of getting under it.
Spring and summer warning: there may be babies under there
Getting this part wrong causes the most damage. Skunks are born in late April and May, and young opossums spend about two months in the pouch before riding on their mother's back. WDFW notes that young mammals generally leave the nest eight to ten weeks after birth. From spring into midsummer, assume an under-deck den is a nursery.
If you seal the hole or scare the mother off for good while the young are inside, they starve under your deck. If the mother can't get back in, she may dig or chew her way through. WDFW's guidance is that if young are present, the most humane choice is usually to leave the family alone until they move on. Skunk kits follow their mother out at about 60 days, and at three months they're nearly full-grown and independent.
If you can't wait, keep the harassment mild. Use a light and an occasional blast from a distance, and the mother will often move her young to another den herself, sometimes within an hour in fair weather. Never use a one-way door when young might be inside. If you find orphaned young, call a licensed wildlife rehabilitator. Don't try to raise them yourself.
Also, don't trap and drive a skunk to a park. Skunks are a rabies vector species. In Maryland, for example, a trapped skunk can't legally be relocated. It has to be released on site or euthanized. Check your state wildlife agency's rules before you set any trap.
Don't skunk your own dog
A pet is the most likely thing in your yard to get sprayed. If a skunk is under the deck, keep dogs inside for the whole eviction, especially at dusk. Minnesota DNR suggests a foaming mix of one quart of 3% hydrogen peroxide, ¼ cup of baking soda, and 1 to 2 teaspoons of mild dish soap for a dog that does get hit. If a pet is bitten or scratched, call a veterinarian.
The horn itself also needs some care around animals you want to keep. Don't fire it close to a dog's ears, and remember that neighbors are also within range at dusk. Our guide on train horn safety around dogs and pets covers safe distances.
FAQ
Will an air horn make a skunk spray?
It can if the skunk feels cornered. Skunks usually warn first by stomping, charging, and raising the tail. Keep the horn out of the exit path and trigger it by remote from more than 20 feet away, and a startled skunk will usually just leave.
Why didn't the opossum run when I blasted the horn?
It may have frozen or "played dead," which is an involuntary shock response, not a sign that it's hurt. Stop blasting, leave the area, and give it time. It will usually recover and leave after dark.
Can I automate the horn so I don't have to sit by the window?
Yes. A motion-triggered setup works for a den entrance, but put the sensor so it fires as the animal approaches, not when your dog walks by. Our motion sensor train horn guide, linked below, walks through the wiring and placement.
Does this work for raccoons too?
The basic approach is the same, but raccoons learn faster and climb into attics. Our raccoon guide, linked below, covers the differences.