If you hear critter sounds in your attic, you can often identify the type of pest problem you have, based on the type of sounds it makes.
If the noise of the rodent in the attic is at night, it’s probably raccoons, rats, or another nocturnal animal. How about the location of the sound? If it’s in a wall or a very tight space, it’s probably a rodent like rats or mice. What about the volume? The heavier the thumping and walking, the larger the animal, such as a raccoon or opossum. If it’s fast and light scampering, it’s probably a rat or mouse (or squirrel, during the daytime). Below is a description of the sounds of several of the major types of animals that live in attics:
Squirrels: Daytime noise, especially in the morning or evening. Fast scampering, medium volume, usually in the attic, but sometimes the walls, and often the eaves, and vents. Their not as loud with one squirrel when it’s just the first female, but when the young grow large enough, you hear the putter-patter from the babies.
Raccoons: You will mostly hear noises at night. You will hear heavy walking or thumping. If the raccoons are mating, then the adults will actually squeal. A nest of baby raccoons has a very distinctive noises.
Rats: Nigh time only, especially shortly after sunset. Light scurrying and scampering, maybe some scratching. You may also hear fast running up or down the walls.
Mice: Like rats, but a lighter noise. Though in actuality, the acoustics of your home, thickness of walls, presence or lack of insulation has more bearing on volume than animal size.
Bats: They are very quiet, but if there are enough of them, you’ll hear them chirping after sunset.
Flying Squirrels: They are nocturnal, and the sound is a lot like rats, although you’re not likely to hear them in the walls the same as with rats.
Birds: Flapping sounds, and chirping. Most of the sound will be during the daytime.