Fall rodent season in Pahrump: why they come inside when the nights cool

The calls change at this time of year. All summer it is scorpions, ants and wasps. Then the nights start dropping and the phone turns over to the same three sentences: something is scratching in the ceiling, there are droppings under the kitchen sink, and the dog will not leave one cabinet alone.

Nothing has gone wrong with your house

Mice and rats have been on your lot all summer. Out in the open desert, in the washes, under a woodpile, in a feed shed, in the irrigated landscaping that stays green while everything around it burns off. Through July and August they had no reason to come in. Water and food were outside, and so were they.

Then the nights cool, the ground dries out, and the desert stops feeding them. At that point your house is the warmest, wettest, safest structure on the property, and it is also the one with a pantry in it. They are not invading. They are relocating, the same week every year.

Where they actually get in

A house does not need a hole. It needs a gap. If you can push a pencil through it, treat it as a door.

• The bottom corners of the garage door, where the rubber seal has curled away from the concrete
• Worn door sweeps on any exterior door you can see daylight under
• Plumbing, gas and electrical penetrations through the exterior wall, especially behind the water heater and under the kitchen
• Weep holes, foundation vents and crawl space screens that have torn or rusted through
• Swamp cooler lines, duct chases and the gap where the roof line meets the fascia
• Anywhere a shed, a lean-to, a patio cover or a block wall touches the structure and gives them a bridge

Roof rats climb, so height is not protection. A tree limb over the roof, a trellis, a stack of pallets against the back wall, a cable run into the eave — any of them is a road.

The signs worth acting on

• Droppings in drawers, in the back of a cabinet, or in a line along a baseboard
• Gnaw marks on the corners of boxes, plastic bins, bags of pet food or dog treats
• A dark greasy smudge along a wall or a beam — that is the same run being used every night
• Scratching or rolling sounds overhead in the evening and early morning
• Pet food disappearing faster than the pet is eating it
• A dog or cat suddenly fixated on one cabinet, one appliance, or one corner of the garage

One dropping in a garage is normal in this valley. Droppings in two different rooms means they are already living inside, not passing through.

Why traps on their own stop working

A trap catches the animals that are already in the house. It does nothing about the opening they used, and it does nothing about the population outside that keeps sending replacements. That is why people tell us they have been catching one a week for two months and cannot understand why it never ends. The trap is working fine. It is just not the part of the job that finishes it.

Loose bait is a separate problem. Bait tossed into a garage, an attic or a crawl space is reachable by a dog, a cat, a curious child and every bird and animal that scavenges out here. If bait is used at all, it belongs locked inside a secured station that is placed deliberately and checked on a schedule.

What actually ends it

• Find the entries first. That means walking the whole exterior, the roof line, the garage and the crawl space, not just setting traps where the droppings are.
• Close them with material a rodent cannot chew through. Expanding foam and caulk on their own get chewed out within the season.
• Take away the draw outside: bird seed, feed sacks, pet bowls left out overnight, fallen fruit, a leaking hose bib, a woodpile stacked against the wall.
• Then keep watching. Secured exterior stations checked on a schedule tell you whether pressure is going up or down instead of leaving you to guess.

One safety note before you clean up

Do not sweep or vacuum rodent droppings, urine or nesting material dry. Doing that puts the dust into the air you are standing in, and that material can carry illness. Open the space up and let it air out first, wet the material down instead of stirring it, wear gloves, and bag it. If it is a heavy build-up in a closed-up attic, crawl space or shed, get advice before you go in there — that is not a job to improvise.

When to call us

If you are hearing it in the ceiling, if you have found droppings in more than one room, or if you have been resetting the same trap for two weeks, the problem is a way in that nobody has found yet. We will come out, walk the property, tell you where they are getting in and what it will take to close it, and the estimate is free. Call (775) 469-0919.