It starts as a faint scratching. Then, a thump. Then, what sounds like a bowling tournament taking place directly above your master bedroom.

Hearing animals in your attic is unsettling. But before you can solve the problem, you need to know what you are fighting. In Louisville, the “Big Three” attic invaders are Eastern Gray Squirrels, Rats/Mice, and Raccoons.

While a professional inspection is the only way to be 100% sure, you can often identify the culprit just by listening to the clock.

The #1 Clue: Time of Day

Animals follow strict circadian rhythms. When you hear the noise is the biggest clue to what species it is.

Daytime Noises (Diurnal) = Gray Squirrels

If you hear the noise primarily during daylight hours—specifically early morning (sunrise to 10 AM) and late afternoon (4 PM to sunset)—you almost certainly have Eastern Gray Squirrels.

• Behavior: They wake up with the sun, leave the attic to forage, come back for a mid-day nap, go out again, and return at dusk to sleep.

• The Sound: Fast, frantic scurrying. You might hear the sound of nuts rolling (like marbles on wood) if they are storing food. They are hyperactive and quick.

• Silence at Night: Gray squirrels sleep at night. If the noise stops completely once it gets dark, it’s squirrels.

Nighttime Noises (Nocturnal) = Rats, Mice, Flying Squirrels, or Raccoons

If the attic is silent all day but comes alive after dark, you are dealing with a nocturnal animal.

1. Rats and Mice

• The Sound: Light scratching, gnawing, or pitter-patter of small feet. It often sounds like it’s in the walls, not just the ceiling.

• Pattern: Consistent scratching in one spot (gnawing) or running along specific paths (following pipes/wires).

2. Southern Flying Squirrels

Yes, Louisville has flying squirrels! They are strictly nocturnal and live in colonies.

• The Sound: Unlike the heavy thumping of a raccoon, flyers sound like a “soft bowling alley.” You might hear acorns dropping and rolling.

• Timing: Peak activity is often late night, from 10 PM to 3 AM.

3. Raccoons

• The Sound: Heavy. Very heavy. It sounds like a human is walking in your attic. You will hear slow, deliberate thumping steps, not fast scurrying.

• Vocalizations: You may hear chattering, growling, or if babies are present, a “chittering” bird-like sound.

• Timing: They leave shortly after dusk to forage and return before dawn.

Other Clues to Look For

Entry Points

• Squirrels: Look for chewed holes in fascia boards, soffits, or gable vents. The holes will be about the size of a baseball with rough, chewed edges.

• Rats: Look for gaps near the foundation, AC lines, or roof vents. They leave dark grease marks (sebum) around the hole from their fur rubbing against it.

• Raccoons: They tear massive holes. Look for torn-open soffits, bent roof vents, or uncapped chimneys.

Droppings (If you can see them)

• Squirrels: Similar to a bean, rounded ends, often scattered.

• Rats: Capsule-shaped, blunt ends, about 3/4 inch long.

• Raccoons: Large, tubular, similar to a small dog’s droppings. Often found in communal piles called “latrines.”

Why Identification Matters

The removal strategy for a squirrel is completely different from a rat.

• Squirrels require one-way exclusion doors mounted on the roof.

• Rats require snap traps and rigorous sealing of foundation gaps.

• Raccoons require heavy-duty cage traps and often baby removal.

If you misidentify the animal, you might set the wrong trap or seal a hole that traps a dangerous animal inside your home.

Hearing noises right now? Don’t guess. Call Critter Removal of Louisville for a free inspection. We’ll identify the intruder and give you a plan to get them out for good.