Rodent Noises at Night: What You Are Hearing in the Attic or Walls

Noises in the ceiling or walls at night in a Jacksonville home usually come from roof rats or house mice. Roof rats make heavier running, scratching and gnawing sounds in the attic and ceiling, often right after dark and before dawn. Mice make lighter, quicker scratching in walls and cabinets. Squirrels are louder but mostly active in the daytime.

Timing, location and sound are the three clues. Here is how to read them.

Roof rats in the attic

Roof rats are the most common nighttime attic noise in Jacksonville. They nest above ground in attics and soffits, and UF/IFAS notes they will travel about 150 yards to reach food or water. Many leave the attic around dusk to feed and come back before dawn, which is when people hear the most.

The sounds are running back and forth, scratching, thumps as they jump down from a beam, and gnawing on wood or wires. You may hear something rolled across the attic floor, often a seed or fruit pit they carried in.

Mice in the walls

Mice are lighter and quicker. They make soft scratching and scurrying sounds inside walls, under cabinets and sometimes in the ceiling. You might hear faint squeaks or chewing. Activity is highest at night and early morning when the house is quiet.

Mice stay close to home. The University of Kentucky's pest control material says they usually travel no more than 10 to 25 feet from the nest, so the noise tends to stay in one part of the house. See mice in the walls.

Norway rats below

Norway rats live low. If you hear scratching under the floor of a raised house, in a crawl space, or along the garage wall at night, Norway rats are a possibility. They are heavier than roof rats, and their burrows outside along the slab or under a shed help confirm it.

Other animals that make noise

Not every attic noise is a rodent:

• Squirrels are active in daytime, especially morning and late afternoon. They sound heavier and make more rolling and scampering noises.
• Raccoons are much heavier, with thumping and sometimes vocal sounds, usually at night.
• Bats make faint scratching and squeaking near dusk as they leave to feed.
• Birds nesting in vents or soffits make sounds in the early morning.
• Some sounds are the house itself: ductwork, pipes or wood expanding and contracting as temperatures change.

If the noise happens mostly in daylight, think squirrel. If it is mostly at night, think rat or mouse.

How to confirm what you hear

Go into the attic during the day with a flashlight, wearing gloves and a mask, and look for:

• Droppings: roof rat droppings are about 1/2 inch long, mouse droppings 1/8 to 1/4 inch, per the University of Kentucky
• Runways or tunnels through insulation
• Dark, greasy rub marks on rafters and top plates
• Gnawed wires, ducts or wood
• Nesting material in corners or under the eaves

Outside, at dusk, watch the roofline, palms and power lines near the house. Rats often follow the same route every night. See rat droppings identification to compare what you find.

Keep a noise log

A few nights of notes make it much easier for you or a technician to figure out what is going on. Write down:

• The time the noise starts and stops
• Which room or part of the ceiling it comes from
• What it sounds like: light scratching, heavy running, gnawing, thumping
• Whether it is louder after rain or a cool night

A pattern that starts at dusk and repeats before dawn over the bedroom closest to a palm or oak points to roof rats using that side of the roof. Light scratching in one kitchen wall at all hours of the night points to mice near a food source. Noise mostly in the morning points to squirrels. Bring the log to the inspection.

If you can, also note what is happening outside: fruit ripening on a tree near the house, a neighbor clearing a lot, a storm the night before. Those details often explain why the noise started when it did.

What to do next

Don't wait it out. Rodents in an attic chew wiring and ductwork, and roof rats breed fast in mild weather. Set traps on the runways if you can safely reach them, and look for the gaps along the roofline.

If you can't tell what it is, or you hear it every night, a rodent inspection will identify the animal and the entry points. For roof rats, rat control pairs attic trapping with sealing.

Common questions

Related reading

• Mice in the walls
• Roof rats
• Rodent Inspection
• Rat Control