What's Living Under Your Deck or Shed This Winter? Raccoon, Possum or Groundhog
Last updated: October 20, 2026
As the cold settles in across Fort Wayne and Northeast Indiana, something moves in under a lot of decks, sheds, and porches. The dark, dry, sheltered space beneath a structure is prime winter real estate for nuisance wildlife, and the animals that take it over aren't picky about sharing a neighborhood with people. Before you block off the opening, tear out skirting, or try to flush it out, it's worth figuring out exactly what you're dealing with — because the right move is different for each animal, and the most common DIY mistake (sealing the hole with an animal inside) is the one thing the traps and exclusions we use are built to avoid.
The Three Usual Suspects in Cold Months
When a homeowner in our area tells us about activity under a deck, shed, or crawlspace in winter, it's almost always one of three animals: a raccoon, an opossum (possum), or a groundhog. They each leave their own set of clues, and telling them apart up front makes the whole job simpler — both for what to expect and for how quickly it can be resolved.
The first big difference is seasonal activity. Groundhogs are true hibernators: as fall ends in Northeast Indiana, they feed heavily to build fat reserves and then retreat into deep burrows to sleep through the winter. That means the animal doggedly defending a burrow under your shed in January is very rarely a groundhog — a groundhog that's still active in the dead of winter is the exception, not the rule. Raccoons and possums, by contrast, stay active all winter. A raccoon won't leave a warm den because it's cold out, and an opossum doesn't hibernate either — it's just less visible. So if you're hearing or seeing activity under a structure in January, raccoon or possum is your bet.
How to Tell the Three Apart
Hole size and shape
Groundhogs dig burrows with an entrance roughly the size of a fist to a basketball, with a distinct fan of freshly excavated dirt kicked out in front of it. A groundhog burrow usually has more than one entrance. Raccoons and possums, by contrast, don't dig their own hole — they squeeze through an existing gap that's already there, like a torn vent screen, a loose skirting panel, or the low lip of a crawlspace. If the hole is part of a dug burrow with a dirt apron, think groundhog. If it's an opening in the structure itself that's been pushed, torn, or pried a little wider, think raccoon or possum.
Tracks and activity time
Raccoons are mostly active at night and leave distinctive hand-like tracks with five toes and claw marks. They're heavy enough that their activity under a structure often sounds like deliberate footsteps, and they're strong enough to tear at skirting and vent screens. Possums are also nighttime animals, but they're slower and quieter — you may hear soft rustling rather than thumping. If you see an animal at all, a possum is usually grayish with a bare, rat-like tail, while a raccoon has the dark mask across its face and a ringed tail. Groundhogs are daytime animals; except for a brief period, don't expect to catch one visiting its burrow at night.
Droppings and smell
A raccoon den builds up droppings that concentrate in one corner, and raccoons have a strong, musky ammonia-like odor that can seep under a deck or into a crawlspace. A possum den carries its own musky scent and often has droppings collecting near a single entrance. A groundhog burrow typically doesn't have the same den odor, because the animal spends most of the day in a burrow designed around digging and hiding rather than living in one sheltered pocket under a structure.
Groundhogs Hibernate; Possums and Raccoons Stay Active
This is the single most useful fact for deciding how to respond in cold months. If it's genuinely winter and you have an active animal under a deck or shed, it's almost certainly a raccoon or possum — both stay active and both will keep using the same sheltered den until the entrance is excluded and sealed. A groundhog that denned for the season has already gone deep and quiet; the empty burrow under a shed can simply be watched until spring, when the timing for trapping it reopens. That seasonal difference also changes how quickly a problem should be treated: a struggling, cold, or displaced raccoon or possum can be more stressed in winter, which is one more reason to handle it with an exclusion and trapping plan rather than leaving it to get by on its own.
Safety First: Don't Block a Hole With an Animal Inside
The most common DIY mistake we see — in every season, but especially when someone's trying to “winterize” a crawlspace — is sealing an entry point before the animal is confirmed out. Block a hole with an animal still inside and you and it both lose: the animal will claw or chew a new opening, often somewhere worse (including into the house), or it will die in place, leaving an odor cleanup under your deck or in your crawlspace. And "the animal" is often plural. Possums frequently den with young riding on their back, and raccoons that set up under a structure in late winter may give birth there once the weather warms — which means the removal has to account for babies that can't leave on their own, not just one adult.
So: do not seal the opening, don't smoke the space out, don't reach in, and don't rely on mothballs or ultrasonic repellers to settle it long-term. What you can safely do while you wait for help is keep kids and pets away from the area, note what time of day you hear activity (that clue helps us identify the animal), and avoid noise or bright lights aimed at the den, which can push a stressed animal deeper into the structure.
Why One-Way Exclusion Plus Trapping Works
Removal is done in two connected steps, and neither works well alone. We place traps where the animal is actually traveling into and out of the den, using humane cage trapping rather than poison — every one of our technicians is licensed and insured. Once we've confirmed the animal (and any young) is out, we install one-way exclusion and seal the entry points so the same den site can't be reused. That's the part a partial DIY repair misses: sealing one gap just sends a raccoon or possum a few feet over to the next weak point in the same skirting. Our follow-up visit confirms the repair is holding, and every job carries our guarantee — if the animal gets back in during the guarantee period, we're back out.
When to Call Us
Call once you've confirmed (or strongly suspect) an animal is denning under a structure and you want it removed humanely and permanently. It's especially worth calling sooner rather than later if there's a chance of young, if the animal sounds large and active (raccoon pressure), if you can smell a strong odor, or if the structure is close to an interior wall where tunneling or chewing could reach inside. We handle the whole thing — identifying the animal, trapping, one-way exclusion, and sealing — across Fort Wayne and Northeast Indiana, with free, usually same-day quotes and seven-day-a-week phone and text support.
If you've figured out it's a raccoon, read our raccoon removal service page. An opossum? See possum removal. And if a groundhog under a shed is the culprit once spring rolls around, our groundhog trapping page covers it.
Frequently Asked Questions
How do I know if it's a raccoon, possum, or groundhog under my deck?
Start with the season and the hole. Groundhogs dig an entrance with a fan of dirt and hibernate in winter; raccoons and possums use an existing gap you can see or hear, and stay active all winter. Raccoons are heavier-limbed, nocturnal, and leave a strong musky/ammonia odor; possums are slower, quieter, grayish with a bare tail, and also nocturnal. Those clues, plus the timing of activity, usually narrow it down before any inspection.
Should I just close off the hole under my deck?
No, not until the animal is confirmed out. Sealing a hole with an animal inside traps it, which often leads to a new hole chewed somewhere worse, or a dead animal and an odor problem. We always confirm the den is clear before we exclude and seal.
Is it dangerous to have wildlife under my deck?
It can be, particularly with raccoons, which are a known rabies vector species and will defend a den if cornered. A possum or groundhog is less likely to be aggressive, but any of the three still creates odor, droppings, and structural risk from chewing and burrowing. It's not something to reach into yourself.
What if it has babies under there in late winter?
Raccoons that den under a structure in late winter may give birth once it warms, and possums often den with young riding on their back. Either way, removal has to account for young that can't leave on their own — we confirm no babies are left behind before we seal the entry point.
Will it leave on its own when the weather warms up?
Not reliably. A raccoon or possum that has picked a sheltered den under your structure will often keep using the same spot until the entrance is actually excluded and sealed. Left alone, it typically just stays — and may raise young there.
TODO-owner: Add one real winter job anecdote here — for example a customer who found a raccoon had settled in under a deck once the cold arrived, and how the exclusion plus trapping cleared it out.