A persistent chewing or scratching sound in your ceiling is almost always caused by wildlife, rodents, or insects nesting in your attic or wall voids. The specific type of animal often depends on the time of day and the volume of the noise.
Rodents are known for their swift movements, so if the scratching sounds are accompanied by scurrying sounds, you're likely hearing a rat or mouse on the move. Rodents chew and they chew loudly and persistently. They constantly chew and gnaw on anything and everything, including drywall and wiring.
Scratching, scurrying, or even chewing noises inside walls typically mean a pest is active—either nesting, moving around, or trying to get in (or out). The volume and frequency of the sound can vary depending on the type and size of the pest. Most homeowners hear these noises at night because many pests are nocturnal.
First up is the noise. If the sounds are in the daytime, especially early morning or evening, you have squirrels in your house. If the noise is at night but very heavy sounding, and slow, it's likely raccoons. Opossums are another option, but they are rarer.
Possible Structural Causes
Thermal expansion and contraction: Wood framing, metal ductwork, and composite materials expand and contract at different rates as temperatures change throughout daily cycles. These movements create audible clicks, pops, and creaking sounds that intensify during rapid temperature transitions.
Rats in the ceiling typically make light scratching, scurrying, and thumping sounds as they move. Because they are nocturnal, you will most likely hear them at night.
Warning signs of a ceiling under stress include:
The telltale signs of ceiling rats
Rats are known for scratching, bumping and squeaking noises. If you're lying in bed and you hear these sounds from your ceiling – particularly at night, that's a pretty strong indication of a potential infestation.
Squirrels: Squirrels make scratching and scurrying sounds that are similar to rats and mice. The biggest difference is that squirrels are diurnal (active during the day). So, ask yourself when the sounds are most pervasive. If during the day, you might have squirrels in your walls.
A raccoon in your attic typically sounds like a heavy, slow-moving adult walking around. Because they can weigh 15 to 40 pounds, their movements are not light. Homeowners often describe the sounds as resembling a heavy human walking or a "drunk person" stomping above the ceiling.
If you see one mouse, you likely have more—potentially 5 to 10 more hidden out of sight. Since mice are highly social, fast-breeding creatures, spotting one usually indicates a family group or an established nest is nearby.
Mice in your walls typically make light, rapid scratching, scampering, and gnawing sounds. Because mice are nocturnal, you are most likely to hear these unsettling, rhythmic pattering noises at night when the house is quiet.
The Amish control mice through non-chemical, self-sustaining methods, relying on active trapping, natural scent repellents, and structural exclusion. Rather than using commercial poisons, they focus on physical barriers and natural predators to keep rodent populations in check.
Since mice are active at night, the sounds they make inside your ceiling may be surprisingly loud. Don't be surprised if they jolt you awake! Upon hearing these noises and confirming they come from the ceiling or attic, it's best to do a visual inspection of the suspect areas.
A sagging or bulging ceiling is a more serious sign of water in the house and possible structural damage — this usually needs immediate attention.
Possums and rats make very different sounds from one another. Rats tend to make a scuttering sound, as their claws tip-tap across your roof cavity. Possums are larger animals and often make more noise. Running sounds and scratching sounds coming from your roof is a good indicator that you've got a possum infestation.
Raccoons in the Attic
Most late winter and spring time raccoon calls are related to females denning in attics. Once a mother raccoon moves in, she is going to be there until the kits are ready to meet the world. This will take about 8-10 weeks if you do nothing and let nature run its course.
Rodents like rats and mice often make persistent scratching, scurrying, or gnawing sounds, especially at night when the loft is quiet. Squirrels can be heard with louder, more forceful scratching or scampering, frequently in the early morning or late afternoon.
Animals in your attic often give themselves away through distinct sounds, foul odors, physical damage to insulation, and visible droppings. Identifying these signs early can help determine which critter has moved in so you can safely and effectively remove them.
So the rat and mouse population is at it's highest by late Summer/early Autumn. As autumn progresses the food sources start to dry up and the vegetation dies back. Rats and mice will feel the cold and will now start to seek cover, alternative food and warmth. This is when they move into buildings.
A rat gnawing sound is a repetitive, rhythmic scraping, crunching, or grinding noise. It happens when rats chew on hard materials—like wood, drywall, or electrical wires—to keep their continuously growing teeth trimmed and sharp.
Yes, rats can easily chew through drywall. Because their teeth continuously grow, they have an instinctual need to gnaw on hard surfaces to wear them down. They can bite through 0.50.50.5-inch thick drywall in less than an hour.
Common nighttime rodent sounds include:
Persistent scratching noises within ceiling spaces or behind wall surfaces. Rhythmic gnawing sounds near baseboards, around plumbing fixtures, or electrical outlets. Rapid scurrying or running movements in attic areas, crawl spaces, or between floor levels.
One of the most active times for rats is during autumn due to their preparation for the cold weather ahead. Rats become more active in September-November as they scavenge for food to stockpile and make nests. When temperatures start to drop, rats are less likely to venture out during daylight hours.
Yes, wild rats will sometimes go near, crawl on, or bite a sleeping human. However, they are naturally cautious creatures and typically only do this if you are actively attracting them or have an established infestation.