Types of Rats in California: Roof Rats, Norway Rats & Woodrats

California is home to two commensal rats that live around people — the roof rat (Rattus rattus) and the Norway rat (Rattus norvegicus) — plus the native woodrat, or “pack rat” (Neotoma), that lives outdoors. By far the most common rat in California, and the one we find in most Fresno and Central Valley homes, is the roof rat (per UC IPM). Telling them apart matters, because where a rat lives decides how you get rid of it.

The rats of California at a glance

Roof rat vs Norway rat vs woodrat

Roof rats — California’s most common rat

Roof rats are the rat we deal with most in Fresno. They’re lean, dark, and built to climb — they reach attics by running along fences, power lines, tree limbs, and vines, then squeeze through gaps as small as a half-inch. The Central Valley’s warm, dry climate and its fruit-and-citrus belt give them year-round food and shelter, which is why we pull them out of attics, garages, and backyard trees all over the area. Read the full roof rats in California guide for ID, signs, and what to do.

Norway rats — the burrowing rat

Norway rats are the heavier, ground-dwelling rat: blunt nose, small ears, and a tail shorter than the body. Instead of climbing, they dig — burrows along foundations, under decks and sheds, in crawlspaces, and near water and sewer lines. They’re less common than roof rats in Fresno but show up around older infrastructure, canals, and properties with easy ground access.

Woodrats (pack rats) — the native outdoor rat

Woodrats are native California rodents — not a structural pest like the other two. They build bulky stick-and-debris nests (middens) and are known for hoarding shiny objects. You’ll mostly see them on rural, foothill, and edge-of-town properties, in woodpiles, sheds, outbuildings, and occasionally nesting in parked vehicles.

Which rat do I have?

Quick test: found it up high (attic, ceiling, fruit tree)? Almost certainly a roof rat. Found it at ground level (burrow, crawlspace, garage floor)? Likely a Norway rat. A stick nest outdoors on a rural lot? A woodrat. You can also identify it by the droppings or by the nest you find.

Is it a rat or a mouse?

If it’s much smaller — palm-sized, with big ears, a thin tail, and tiny rice-grain droppings — you may have a house mouse rather than a rat. See mouse vs rat to be sure, since the two are controlled differently.

What to do if you have rats in Fresno

Whatever the species, the fix is the same approach in a different order: inspect, identify, seal the entry points, then trap — exclusion first, with bait used carefully and never as the only tool. See our rat control and rodent exclusion services, or start with a no-cost inspection.

Explore rodent control in Fresno

Rats in California — FAQ