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How to Get Rid of Mice & Rats in Fresno
A Central Valley homeowner’s guide to rodents — how they get in, what actually clears them out, and the point where trapping alone won’t keep up.
Rodents are a year-round problem in the Central Valley, and they rarely arrive one at a time. House mice and roof rats are built to live alongside us — they slip through gaps you would never think twice about, breed quickly once inside, and chew through wiring, insulation, and food packaging. By the time you hear scratching in a wall or find droppings in a drawer, there is usually a small population already established. This guide covers how rodents get into Fresno homes, what genuinely gets them out, and the point where traps alone stop keeping up.
Seal the gaps they get in through, set snap traps along the walls where they travel, and cut off food and water. Skip poison bait indoors — a rodent that dies inside a wall is a smell-and-fly problem you cannot reach. For an active infestation, the real fix is finding and sealing every entry point, which is most of what a professional actually does.
Why rodents get into Fresno homes
Our mild winters and long growing season keep rodents active all year, and cooler nights in fall and winter push them indoors looking for warmth and food. Three rodents show up most in Fresno homes, and the fix is a little different for each:
House mice — small and gray-brown, the most common indoor rodent. A mouse can squeeze through a gap the size of a dime, breeds year-round, and stays close to its food source, so a few quickly becomes many.
Roof rats — sleek, dark, and excellent climbers. They are very common in the Central Valley, drawn to citrus and fruit trees, and they enter up high through the roofline, vents, and attic. If you hear movement in the ceiling or attic at night, roof rats are the usual suspect.
Norway rats — larger and heavier, they stay low: crawlspaces, garages, burrows along the foundation, and anywhere near water. They get in through gaps near the ground and damaged vents.
Knowing which one you have matters, because roof rats are an up-high, climb-in problem while mice and Norway rats squeeze in down low — and that changes where you seal and where you set traps.
A house mouse foraging. Mice stay close to food and can slip through a gap the size of a dime.
Signs you have rodents
Droppings — small dark pellets in drawers, cabinets, the pantry, or along walls. This is usually the first hard evidence.
Gnaw marks and chewed packaging — on food boxes, wiring, baseboards, and stored items. Rodents chew constantly to keep their teeth filed down.
Grease and rub marks — dark smudges along baseboards and entry points where their oily fur drags as they follow the same routes night after night.
Scratching or scurrying after dark — in walls, ceilings, or the attic, where rodents are most active.
Nests and a musky odor — shredded insulation, paper, or fabric wadded into hidden corners, plus an ammonia-like smell in enclosed spaces.
How to get rid of mice and rats yourself
For a light, early problem, DIY can work — but only in the right order. Sealing comes first; trapping without sealing just empties a doorway that keeps refilling.
1. Find and seal the entry points. This is the step that actually solves it. Walk the exterior and seal gaps with steel wool packed into caulk, hardware cloth over vents and weep holes, and fresh door sweeps. Check the roofline and where pipes and cables enter for roof rats. Mice need only a dime-sized hole; rats a quarter-sized one.
2. Set snap traps along the walls. Place plenty of them perpendicular to the wall, trigger toward the baseboard, where rodents travel. Bait with a dab of peanut butter. Snap traps are more effective and more humane than glue boards, and they keep the rodent out of the wall.
3. Cut off food and water. Store food and pet food in sealed containers, fix drips and leaks, empty the trash, and clear clutter that gives them cover. Rodents will not stay where they cannot eat or drink.
4. Skip poison bait indoors. Indoor rodenticide is the most common DIY mistake — the rodent dies inside a wall or floor void, leaving an odor you cannot reach and a fly problem, and it poses a secondary-poisoning risk to pets and to the owls and hawks that eat rodents. Use traps inside; leave any bait stations to the exterior, in tamper-resistant boxes.
5. Clean up safely. Do not sweep or vacuum droppings dry — that can put rodent-borne germs into the air. Spray with a disinfectant, let it sit, then wipe with gloves and bag it.
Ultrasonic “repeller” plug-ins do not clear an infestation — there is no good evidence they work. Indoor poison bait creates dead-in-the-wall odor problems. And a single trap will never keep up with a breeding population — you need many, maintained over days.
When it is past DIY
DIY can knock down a minor mouse problem. It usually will not clear rats, which are cautious and quickly learn to avoid traps; an infestation that keeps coming back after weeks of effort; rodents living in an attic, wall void, or crawlspace you cannot safely reach; or droppings turning up in several rooms at once. At that point you are fighting a population whose entry points and harborage you cannot find — which is exactly where a professional pays for itself.
How the pros clear it
Our rodent control starts with a full inspection to find every entry point — including the roofline and attic routes most homeowners miss — followed by professional exclusion to seal them, strategic trapping inside, and tamper-resistant exterior stations where appropriate. We monitor, return to clear and reset, and give you the sanitation and yard guidance that keeps them from coming back. The goal is not just the rodents you can see today; it is closing the door they came in through.
See our rodent control process →How to keep rodents from coming back
Once they are out, prevention is mostly about the building envelope and the yard. Keep the gaps you sealed sealed, trim tree limbs and shrubs back from the roof so roof rats cannot climb in, pick up fallen fruit, store food and pet food sealed, and declutter the garage and storage areas. For homes with ongoing pressure — especially near orchards, canals, or older neighborhoods — most Fresno homeowners stay on a recurring plan that keeps the perimeter monitored and catches new activity early.
Rodent control FAQ
How do I know if I have mice or rats?
Mice leave small rice-sized droppings and stay low; roof rats leave larger droppings and are usually heard up in the ceiling or attic. Mice are curious and trap easily, while rats are cautious and harder to catch. The size and location of the droppings is the quickest tell.
Is rodent poison safe to use at home?
We do not recommend poison bait indoors. Rodents often die inside walls — creating an odor you cannot reach — and the bait poses a secondary-poisoning risk to pets and to the owls and hawks that eat rodents. Snap traps indoors are safer and more reliable.
How long does it take to get rid of rodents?
A small mouse problem can clear in a couple of weeks with sealing and trapping. Rats, or a larger infestation, usually take a multi-visit plan over several weeks — most of which is finding and sealing every way they get in.
Why do I only hear them at night?
Rodents are nocturnal, so scratching and scurrying in the walls or ceiling after dark is often the first sign. Hearing it overhead usually points to roof rats up in the attic.
Do I really need to seal the house?
Yes — sealing entry points is the single most important step. Trapping without sealing just removes the rodents currently inside while leaving the door open for the next ones. Exclusion is what makes the fix last.
Hearing scratching in the walls? Let’s find how they’re getting in.
Call (559) 472-8200 or request a no-cost inspection — we’ll find every entry point and seal them out for good.