Rodents are active in El Paso all year, but the problems shift with the seasons. Woodrats breed mainly from January through September. Roof rats breed year round with peaks in late winter and late spring. The summer monsoon brings storms that can flood burrows. Fall cold sends mice into garages and houses, and summer heat makes any dead rodent in an attic a strong odor problem.
Here is what to watch for, season by season, and what to do about it.
Winter: December to February
Cold nights push mice into garages, sheds and houses looking for shelter. Texas Tech reports that roof rats breed year round with a peak in February and March, and woodrats start their main breeding season in January.
- Check garage door seals before the first cold snap and replace worn ones.
- Look for droppings in stored holiday boxes and seasonal gear.
- Set snap traps along garage walls if you see signs.
- Check vehicles that sit for sticks and nesting under the hood.
Spring: March to May
Spring winds and new growth bring more activity outside. Roof rats have a second breeding peak in May and June, per Texas Tech, and woodrats are deep in their breeding season.
- Walk the yard for woodrat middens in cactus and rock beds and behind sheds.
- Clear wind-blown debris and brush along block walls.
- Trim tree limbs back from the roof.
- Schedule any roof or cooler work, and have gaps around cooler ducts sealed while the cooler is being serviced.
Summer and the monsoon: June to September
Summer heat turns attics into ovens. A dead rodent in an attic or wall smells fast, so check traps in hot spaces often. The National Weather Service office in El Paso notes that the monsoon typically starts in early July and ends around September 24, and that September is the city's third-wettest month. Its normal for August alone is 1.67 inches of rain.
Heavy storms can flood burrows and wash rodents toward higher, drier ground, which can mean garages and houses. Standing water after storms is also a reason to avoid wading where rodents are active, since leptospirosis spreads through infected animals' urine in water and soil, according to the CDC.
- Check traps in attics and garages more often in hot weather.
- After big storms, look for new droppings in garages and sheds.
- Keep pet food and water dishes inside overnight.
Fall: October and November
As nights cool, mice move indoors. Fall is the best time to seal a house before winter.
- Check gaps around pipes under sinks and at the water heater.
- Inspect stucco cracks at the slab and repair them.
- Store bird seed and pet food in metal cans.
- Move firewood away from the house and off the ground before you stack the winter supply.
A fall inspection and sealing is usually cheaper than chasing mice through the winter.
A month-by-month cheat sheet
Use this as a reminder list. Each line is a quick task.
- January: check stored holiday boxes for droppings and nesting.
- February: look over the attic hatch and roof edges, since roof rats breed heavily in late winter.
- March: walk the yard for woodrat middens as spring growth starts.
- April: trim tree limbs back from the roof and clear wind-blown debris along walls.
- May: have the evaporative cooler serviced and the openings around it sealed.
- June: check traps in hot attics and garages often.
- July and August: after big storms, look for new droppings in garages and sheds.
- September: check the yard for burrows and nests as the monsoon winds down.
- October: seal gaps before the first cold nights.
- November: replace worn garage door seals and move firewood away from the house.
- December: check vehicles that sit for sticks and nesting under the hood.
Why fall sealing pays off
Sealing before mice move in means no trapping, no droppings and no cleanup. A fall visit to check gaps around pipes, the garage door and the roof costs less than handling an infestation in January. Our rodent exclusion page explains what sealing includes.
Wind and dust storms
Spring winds pile tumbleweeds and debris against block walls and fences. Clear those piles, since they give rodents cover right next to the yard.
Year-round habits
Some steps help no matter the season.
- Keep garbage in cans with tight lids, as the CDC recommends.
- Keep clutter off garage floors and store items in lidded bins.
- Clean droppings the CDC way: air out, gloves, bleach solution, wipe, double-bag.
- Check vehicles, mowers and equipment that sit for nests.
For pack rats around parked cars, see our pack rats in car engines article. For trash and yard rules, see the El Paso trash and yard guide.
Frequently asked questions
When are mice worst in El Paso?
Fall and winter, when cold nights push them indoors, though they can be active all year.
When do pack rats breed?
Texas Tech says the woodrat's main breeding season runs from January to September.
Does the monsoon bring more rodents?
Heavy storms can flood burrows and push rodents to drier shelter, so check garages and sheds after big rains.
When is the best time to rodent-proof a house?
Early fall, before cold weather sends mice looking for a way in.
Do rodents hibernate in El Paso winters?
House mice and rats do not hibernate. They stay active and look for warm shelter, which is why winter brings them indoors.
Sources
- Texas Tech University, Mammals of Texas: White-toothed woodrat
- Texas Tech University, Mammals of Texas: Black rat
- National Weather Service El Paso: August 2024 climate digest (PDF)
- CDC: Leptospirosis clinical overview
- CDC: How to seal up to prevent rodents