Rats are social animals that use a variety of sounds to communicate. These vocalizations convey information about their emotional state, social status, and environmental conditions. While many sounds are beyond human hearing, others are distinct and can indicate their presence.
Sounds Rats Make
Rats produce both audible and ultrasonic sounds. Ultrasonic vocalizations, which range in frequencies above 20 kHz, are a primary form of communication for rats and are crucial for many of their social behaviors. These high-frequency sounds often require specialized equipment, such as a bat detector, to be made audible to humans.
Among the sounds humans can detect, squeaks can signal various emotions, from distress or pain to excitement or a warning. Rats may also produce chattering sounds, known as bruxing, by grinding their teeth. This behavior can indicate contentment and relaxation, similar to a cat’s purr, but can also occur when a rat is stressed or anxious. Hissing is another audible sound, often used as a warning or a sign of aggression, particularly during conflicts. Beyond vocalizations, rats create non-vocal sounds such as scratching from their claws as they move, gnawing on surfaces to wear down their continuously growing teeth, and thumping noises as they scurry or move within structures.
Why Rats Vocalize
Rat vocalizations serve diverse purposes in their social dynamics and survival. Ultrasonic calls are important for social interaction, including greetings, play, and mating signals. For example, 50 kHz calls are often associated with positive emotional states and are emitted during playful interactions or when rats anticipate rewards. Conversely, 22 kHz calls frequently signal a negative emotional state, such as fear, pain, or the presence of a predator.
Alarm calls, often high-pitched squeaks or ultrasonic bursts, warn colony members of danger. Vocalizations are also crucial for communication between mothers and pups; infant rats emit high-pitched ultrasonic distress calls when separated from their mothers. Non-vocal sounds, like gnawing, serve practical functions such as maintaining dental health and creating pathways to food or shelter.
Distinguishing Rat Noises
Identifying rat noises in a home involves paying attention to the sounds’ volume, frequency, location, and patterns. Rat movements, such as scurrying or scratching, tend to be louder and more deliberate than those of smaller pests like mice, due to their larger size. These sounds are frequently heard within walls, attics, or basements, especially at night, as rats are nocturnal.
While mice often produce high-pitched squeaks audible to humans, many rat vocalizations, particularly communication calls, are ultrasonic and inaudible without special equipment. Therefore, persistent gnawing or loud scurrying sounds coupled with occasional squeaks or chattering may indicate rats. Sounds like a “rolling” noise, similar to marbles, might suggest squirrels, while heavier thumps could be raccoons.