Rodent Noises at Night: What You Are Hearing and Where

Mice: light and quick

Mice are small, about half an ounce according to University of California guidance, and they sound like it. Expect quick, light scratching and pattering, often moving along a wall. You might hear faint squeaks. Mice are active mostly at night and make many short trips; University of Kentucky pest training notes they visit food sources 20 to 30 times a night.

Mouse noise is often near the kitchen, along exterior walls near the floor, or in the ceiling just above a kitchen or bathroom. See mice in the walls.

Rats: heavier and louder

Rats weigh many times more than mice. Roof rats run about 5 to 10 ounces and Norway rats about 7 to 18, per University of California guidance. Rats make heavier running sounds, thumps, and gnawing that can sound like scraping or chewing on wood.

In Memphis, rats overhead are usually roof rats. Noise in the attic that starts around dusk and comes back before dawn is the classic pattern. Rats under the floor, in a crawl space, are more often Norway rats. See rats in the attic.

Squirrels and other animals

Not every noise overhead is a rodent you can trap with a snap trap. Squirrels are active in daylight, especially in the early morning, and make louder running and rolling sounds as they move nuts around. Raccoons are much heavier and usually make thumping, walking sounds at night. Birds nesting in vents make chirping and fluttering sounds in spring.

Timing is the best clue. Mostly-night noise points to rats or mice. Mostly-day noise points to squirrels.

Where the noise points

Where you hear it helps find the entry:

• Ceiling or top of the wall: attic, often roof rats or mice entering at the roofline
• Inside a wall near the floor: crawl space, slab gap or plumbing chase
• Under the floor: crawl space, often Norway rats or mice
• Behind kitchen cabinets: pipe gaps under the sink or behind appliances
• Garage ceiling or walls: garage door gaps or a shared attic

Keep notes for a few nights: time, place and type of sound. That record helps a technician plan the first visit.

What to check before you call

With a flashlight and gloves:

• Check the attic near the hatch for droppings and trails in insulation
• Look under sinks for droppings and gnawed pipe insulation
• Check the garage along the walls
• Walk outside and look at the roofline for gaps and limbs touching the roof, and at the foundation for burrows

Do not seal interior gaps before the rodents are trapped out; that can trap them in the walls.

Noises from the HVAC system

Sometimes the noise comes through the vents. Scratching or scurrying that seems to come from a floor register or ceiling vent can mean rodents in or on the ductwork, in the attic or crawl space. A musty or urine smell when the system runs is another clue.

Rodents can tear flexible duct and nest inside. If you suspect it, have the technician check the ducts during the inspection, and have an HVAC contractor repair any damage.

Keep a noise log

A simple log over three or four nights helps a lot. Note:

• The time the noise starts and stops
• The room and the wall or ceiling area
• The type of sound: scratching, running, gnawing, thumping, squeaking
• Any droppings or damage you find the next day

Bring the log to the inspection. It helps the technician decide whether to start in the attic, the crawl space or the walls, and whether it sounds like mice, rats or something else.

If you have pets, note how they react too. A dog or cat that fixates on one wall or ceiling spot is often hearing activity you cannot. That spot is worth checking for gaps, droppings and rub marks on both sides of the wall.

Why the noise matters

Rodents in the walls and attic do more than keep you up. They gnaw wiring, soil insulation and leave droppings that need careful cleanup. In Memphis, where long warm seasons let them keep breeding, a few rodents can turn into a bigger group fast.

If the noise keeps up for more than a few nights, a rodent inspection can confirm what it is and how it gets in.