Las Vegas: the mouse-proof standard.
Every home can be made mouse-proof. Focus on the smallest invader, the mouse, and seal every gap it could use. Mice come in for shelter, so sealing the gaps is what keeps them out.
The mouse-proof standard
Southern Nevada’s health district tracks roof rats in the Las Vegas Valley, documented there since 1990, and covers Norway rats, mice and pigeons too. (SNHD)
Seal for the smallest invader. Build every seal to keep out a mouse, and you’ve closed the gaps the bigger ones use too.
A young mouse can get through a gap about the width of a finger. The mouse-proof standard means every gap that size or bigger, on the outside of the house, is closed for good: back it with 1/4-inch hardware cloth (stainless or heavy galvanized) or exterior-grade metal, then seal it in with polyurethane, RTV or acetoxy construction sealant. Vents stay open, with hardware cloth over them. Weep holes are never plugged solid.
Rats, pigeons and bats use gaps like these too. Seal to the mouse-proof standard and those gaps are closed to them as well: one standard, not a separate fix for each animal.
The common mistake: stuffing a gap with steel wool or foam. Mice chew through foam, and steel wool rusts and pulls apart, so the gap opens again. Neither one is a lasting seal.
Where to look first
- Where the wall meets the slab
If your home is block or stucco on a slab, look closely along the line where the wall meets the slab, starting at the corners. Weep holes stay open: cover them with breathable guards or hardware cloth.
Where materials meet - Lines through the wall
Every pipe, cable and hose bib through the wall leaves a gap around it. Check each one with the finger-width rule.
Utility lines - AC lines and chases
Look where the AC line set goes through the wall, and along any chase or cover that runs up the wall.
AC line sets - Garage door corners
The bottom corners of the garage door, where the seal meets the jamb, are a common gap.
Garage door corners - Doors
Check every outside door for daylight at the bottom and sides.
Doors - Rooflines and roof returns
Look up at the soffits, roof returns and eaves with a flashlight. Screen vents with hardware cloth and keep them open.
Rooflines and soffits
Check for bats before you seal
Before you seal any gap up high, shine a strong flashlight up into the shadow: rooflines, roof returns, attic and soffit vents. Look for droppings, dark rub stains, a clean hole through the cobwebs, or bats tucked in the gap. If you see any, don’t seal it yourself, because bats need a proper exclusion so none get trapped inside.
Never seal anything in. If something could be living behind the gap, don’t seal it yet. On a two-story house, when in doubt, assume bats. Don’t touch a bat, alive or dead (CDC). If you think you’ve had contact with one, talk to your health department (CDC).
Bats are protected in many places. Check your local rules on timing before you exclude them.
Mice and hantavirus in Southern Nevada
In Southern Nevada, the deer mouse appears to be the one spreading hantavirus at elevations above 5,000 feet (SNHD). Because it’s hard to tell one kind of mouse from another, the health district advises avoiding all rodents (SNHD).
The health district notes that built-up pigeon debris may attract mice, rats and flies, and that pigeons can carry diseases. (SNHD)
Catch the ones inside once
Once the outside is sealed, catch any mice still inside with enclosed snap traps set along the walls, out of reach of kids and pets. Never poison.
Clean up droppings safely
- Open doors and windows for 30 minutes first, and stay out while it airs.
- Put on rubber or plastic gloves.
- Don’t sweep or vacuum droppings. It puts dust into the air.
- Spray droppings and urine with a disinfectant, or 1 part bleach to 9 parts water, until very wet. Let it soak 5 minutes.
- Wipe up with paper towels and throw them out in a covered trash can.
- Mop or wipe the area with disinfectant, then wash your gloved hands, take the gloves off, and wash your hands again.
Source: CDC, How to Clean Up After Rodents. Asthma or allergies at home? Mouse allergen settles in household dust, and NIEHS researchers linked higher levels at home to more asthma symptoms in people with allergies (Salo et al., 2009). Sealing the gaps and cleaning up this way both help.
Pro matching is in Southwest Florida for now. The free basic check and the guides work anywhere. Not sure what you’re looking at? Send a photo.
Sources
- Southern Nevada Health District, Rodent Pests
- Southern Nevada Health District, Hantavirus Pulmonary Syndrome (HPS)
- Southern Nevada Health District, Pigeon Prevention and Clean-Up Guidelines
- Centers for Disease Control and Prevention (CDC), Preventing Rabies from Bats
- Centers for Disease Control and Prevention (CDC), How to Clean Up After Rodents
Health facts on this page were checked against each source on October 30, 2026.
Find the gaps. Seal them for good. Catch the ones inside once. No poison, ever.