Finding the source
Map the smell
Walk the room with doors closed and HVAC off. Odor is usually strongest close to the source, and it often concentrates at the lowest point of a wall cavity.
Look for flies and stains
Flies gathering at a window, outlet or baseboard, or a damp stain on drywall, often mark the spot.
Check the obvious first
Attic, crawl space, the basement ceiling, behind appliances, inside the dryer vent and in chimney flues.
Consider the HVAC
An animal in a duct will spread smell to every room that duct serves. Odor that rises when the blower runs is a clue.
Bring in help when it is in a wall
A wildlife control or odor professional can narrow the spot so the opening is small and in the right place.
Open the wall or wait it out?
Small animals eventually dry out and the smell fades, but the timing rarely suits a listing.
| Open, remove and repair | Wait for it to fade |
|---|---|
| Odor drops quickly once the remains and stained materials are out | No drywall repair |
| Requires a small drywall cut and patch, then paint touch-up | Can take a couple of weeks or longer depending on the animal and temperature |
| Allows cleaning and treatment of the cavity | Flies and staining may appear during showings |
| Gives a clear record if a buyer asks | Buyers and agents who notice it will ask what is behind the wall |
Fixing the way in, not only the animal
Once the remains are out, the stained drywall or insulation should be removed, the cavity cleaned, and the opening patched and painted. The patch needs to blend well enough for photos, which means planning time for drying and a second coat. If the listing photos are already done, a small, well-matched patch inside a closet is easy to explain; a fresh scar on a living room wall is not.
The other half of the job is the entry point. Rodents slip through small gaps around utility penetrations, under garage doors and at foundation vents, and birds and squirrels find gaps at soffits and roof vents. Older homes in Denver's established neighborhoods often have more of these openings than newer ones. Sealing them protects the listing from a repeat in the middle of showings and gives the buyer one less concern.
If the animal turns out to be inside the ductwork or a chimney, include an HVAC or chimney technician. An open supply duct or a missing chimney cap is an inspection item in its own right.
General information for the Denver area, not a quote or professional advice. In an emergency, call 911.