Rodent articles · Updated November 4, 2026

Noises in the ceiling or walls at night: rats, mice or something else?

Running and scratching over the ceiling after dark usually means roof rats in a San Antonio attic. Light, quick scratching low in a wall is more often mice. Noise at dawn and dusk points to squirrels instead.

If you hear running and scratching over the ceiling after dark, think roof rat first. Roof rats are night animals and San Antonio attics suit them all year. Light, fast scratching low in a wall is more often a house mouse. Sounds that start at sunrise or just before dark point to squirrels, which this line doesn't handle.

Timing, location and the kind of sound tell you a lot. A flashlight and a few minutes in the attic tell you the rest.

Running and scratching overhead after dark

This is the classic roof rat sound: quick runs across the ceiling, a pause, then running back. It's loudest in the first few hours after dark and again before dawn. You might hear scratching where the roof meets the wall, which is often near the spot they get in. A thump can mean a rat jumping down from a rafter onto the insulation.

Roof rats follow the same routes every night, so the noise tends to repeat over the same rooms. Note which rooms. It helps the technician find the activity.

Light scratching inside a wall

Mice in a wall cavity sound light and quick, with scratching and short scurries, often low in the wall near the kitchen or a bathroom. They come out to eat at night and go back in. If the sound is behind the kitchen sink or the stove, check under the cabinets for droppings. Our mice in walls page explains how technicians handle them without cutting drywall.

Gnawing

A steady scraping or grinding sound is chewing. Rats and mice gnaw on wood, wiring, duct and the plastic around pipes. Gnawing in the attic near the air handler or along a wire run is worth checking soon, since chewed wiring is a fire risk and chewed duct leaks air into the attic.

Noise at dawn and dusk

Squirrels are day animals. If the noise starts at first light, goes quiet midday and picks up again in the late afternoon, it's probably a squirrel. Squirrel noise also tends to be heavier and bouncier. San Antonio has plenty of squirrels in the same big oaks and pecans that roof rats use. Read rat or squirrel in the attic to tell them apart, and call a wildlife company for squirrels.

Heavy thumps and walking

Sounds that are heavy, slow and clearly bigger than a rat, like something walking, usually mean a larger animal such as a raccoon or an opossum. Those need a wildlife removal company. Birds in a vent or soffit make fluttering and chirping sounds, mostly in the early morning.

When the noise changes with the seasons

Roof rats stay in San Antonio attics all year, so the noise doesn't stop in summer. Many people notice it more in fall, when pecans drop and citrus ripens and rats are busy carrying food, and right after a cold front, when rodents move deeper into the house and you start hearing them in the walls as well as overhead.

Mice follow a similar pattern. A few cold nights can push them from the garage into the kitchen walls, and that's often when people first hear them.

Keep a simple noise log

Before you call, jot down a few nights of notes. It takes a minute and helps the technician more than you'd think:

• Date and time you heard it
• Which room, and whether it was overhead or in a wall
• What it sounded like: running, scratching, gnawing, thumping
• Anything you found the next morning: droppings, chewed food, a moved object

Noise that comes from the walls near the roof

Some of the most confusing sounds come from inside the top of an exterior wall, where the wall meets the attic. That's a roof rat route. Rats get in at the eave, drop into the gap at the top of the wall, and travel down a few feet before climbing back up. People often hear it as scratching inside a bedroom wall up near the ceiling. A technician will check the soffit and the top plate above that spot from the attic side.

How to confirm what's up there

Go up the attic ladder in the daytime with a good flashlight. Look along the top plates, on the ductwork and on the insulation near the eaves. Rat droppings, trails pressed into the insulation and dark greasy rub marks on rafters mean rats. Compare the droppings with our droppings guide.

If you can't get into the attic safely, a technician can. Tell them when you hear the noise, which rooms, and whether it's overhead or in the walls. That description alone gets them most of the way there.

Related reading

• Rat or squirrel in the attic? How to tell the difference
• Rat droppings vs mouse droppings: how to tell them apart
• Roof Rats, Fruit Trees and Your Attic: A San Antonio Guide

Related services: Roof Rat Control, Mice in Walls Removal, Rodent Inspection