If you hear a knocking sound in your attic, this is a fairly good sign that a creature of some sort has taken up residence in that area. At times you will hear a knocking, while other times you will notice a scurrying noise, thumping sound, or something else. Though a random knocking noise that only happens once does not necessarily imply anything, repeated similar sounds are a sure indication that an animal is living in your attic. Now, you will only have to determine what sort of creature is making the noises in question then take action to get them out of the attic before it is possible to clean it.
The first step to determining which animal is creating the knocking sound on your attic is to look closely at the timing of the noise. Specifically, whether it occurs at night or during the day. This can allow you to narrow down the possible animals a great deal as some are nocturnal while some are diurnal. If, for example, you hear the sounds throughout the day, especially right before sunset in the early evening and in the morning, you're very likely to have squirrels. If the noises, on the other hand, typically happen during the night with the occasional daytime noise thrown in, raccoons might be the culprit. A bit of research can allow you to narrow down the possibilities.
Is It A Knocking noise Or Something Else? Next, you need to determine whether it really is a knocking noise or something else, like a pitter-patter, slithering noise, scurrying noise, or beating. A milder thumping typically indicates a bigger animal like a possum or raccoon. If the sound is not near a knocking, but rather more like a pitter-patter or scurrying noise, then it can be rats or mice. In the case of thicker scurrying, think about squirrels.
When you hear the creature making vocalizations it’s another great indicator of what's creating the knocking noise in your attic. Raccoons are common culprits if there's a vocal growl or chattering sound and baby raccoons are among the noisiest creatures to have in your attic. Chirps will obviously be bats and birds tend to create high-pitched chirps which you might not have previously heard.
Whatever type of creature is causing the knocking noise in your attic, you should attempt to remove from the space when as soon as possible. This is the best method to decrease the damage they cause and minimize your risk of disease.