Short Answer 
To identify a rodent infestation, listen for characteristic noises like squeaks and shuffles, especially at night. Additionally, detect unpleasant oily odors and look for signs such as gnaw marks, droppings, and nesting materials to confirm their presence.
Step 1: Recognize Noises
One of the primary indicators of a rodent infestation is the presence of noises like squeaks and shuffles. These sounds are typically heard at night when rodents are most active. Pay attention to these sounds, as they can signal the proximity of nesting rodents. Common noises to listen for include:
- Squeaks
- Shuffling
- Scurrying
Step 2: Detect Unpleasant Odors
A distinctive oily or greasy smell is another significant sign of rodent activity. This musty odor often indicates that rodents are nesting nearby. If you notice any unusual smells in your living space, it’s essential to investigate further, as this can be a clear indication of a rodent problem. Look for these odors in areas like:
- Basements
- Attics
- Behind walls
Step 3: Look for Additional Evidence
In addition to sounds and smells, be on the lookout for other signs such as rodent gnawing. Although not mentioned initially, gnaw marks on materials or structures indicate rodent activity. Remember that dead insects and eggs are typically associated with other infestations and not rodents. Therefore, focus on the following signs for confirmation:
- Gnaw marks or damaged items
- Droppings
- Nesting materials