Mice vs. Rats: How to Tell the Difference

House mouse

Roof Rat

It’s 2 a.m. You hear scratching in the wall, and your stomach drops. Is it mice? Is it rats? In the Rialto and Fontana area, both are common—but they don’t behave the same. Knowing which one you’re dealing with helps you stop the damage faster and keep them from coming back.

At TruPest Solutions (local, family-owned in Rialto), we deal with this every day. Here’s the quick, clear guide—written for homeowners.

What They Look Like (and Why Size Matters)

Mice are small and delicate: about 5–7 inches from nose to tail, with big ears and a thin, lightly haired tail. They’re curious and will sample lots of food spots.

Rats are larger and stronger: often 12–18 inches nose to tail, with thicker bodies and a scaly tail. Roof rats are sleek climbers; Norway rats are heavier and ground-dwelling.

Why it matters: bigger animal, bigger bite. Rats chew more aggressively and can cause serious structural and electrical damage.

The Damage You’ll See

• Mice: Chewed food packaging, shredded insulation for nests, tiny pepper-like droppings. They contaminate surfaces quickly because they explore a lot of areas in one night.

• Rats: Larger gnaw marks, damaged wiring (fire risk), chewed plastic and wood, ruined attic insulation, and even burrows that undermine slabs or patios.

Either way, waiting only multiplies the problem. Rodents breed fast, and every week you delay usually means more damage.

Where They Hide Around Rialto & Fontana

• Roof rats (very common here): Attics, rafters, eaves, fence lines, and fruit/palm trees. If you hear heavier scratching overhead at night, that’s a clue.

• Norway rats: Crawlspaces, garages, under decks and sheds, near trash bins and stacked lumber. Look for burrow holes along the foundation.

• House mice: Kitchens, pantries, laundry rooms, under appliances, cabinet voids, and cluttered garages.

A quick tell: droppings size. Rice-grain and small = mice. Larger, blunt or pointed = rats. Greasy rub marks along travel routes suggest rats, too.

Why They’re Choosing Your Home

Food, water, shelter—that’s it.

• Food: Pet food, bird seed, open trash, unsealed pantry items, and fruit that drops from citrus trees.

• Water: Leaky hose bibs, AC condensation, puddles, and pet water bowls.

• Shelter: Gaps around garage doors, utility penetrations, worn door sweeps, overgrown vegetation touching the house.

• Season & construction: Cooler nights or nearby construction push rodents to new hiding spots—often yours.

DIY vs. Professional: What Actually Works

A couple of snap traps might catch a few, but they won’t solve the source. The fix that lasts is a professional, integrated approach:

1. Thorough inspection & ID -We confirm if it’s mice, roof rats, or Norway rats and map entry points, runways, and nests.

2. Targeted removal- Species-specific trap setups and placements (and, when appropriate, professional baits) that homeowners don’t have access to.

3. Exclusion (seal-up)- We close gaps as small as ¼–½ inch, add door sweeps, screen vents, and secure utility penetrations. If you don’t seal, they return.

4. Ongoing prevention- In Rialto and Fontana, pressure is year-round. Recurring monitoring keeps your home protected.

Simple Prevention You Can Start Today

• Store pet food and bird seed in sealed containers.

• Pick up fallen fruit and keep trash lids closed.

• Trim trees and shrubs away from the roofline; reduce ivy on walls.

• Fix leaks and eliminate standing water.

• Upgrade worn garage seals and weatherstripping; add ¼" hardware cloth to appropriate vents (without blocking airflow).

Need Help Fast?

If you’re hearing scratching, finding droppings, or seeing gnaw marks, we’ll identify the culprit and handle everything—from removal to seal-up.

Call TruPest Solutions at 951-334-5288 for prompt, local rodent control in Rialto, Fontana, and nearby communities.