Rats possess a complex world of communication, largely through various vocalizations. Though common in human environments, their sounds are often misunderstood. Understanding these sounds offers insights into their social lives and emotional states. This exploration delves into the actual sounds rats produce and their significance.
Do Rats Growl? The Direct Answer
Rats do not growl like larger mammals such as dogs or cats. The concept of a “growl” as a low, guttural warning sound is not typically part of a rat’s vocal repertoire. Misconceptions may arise from other aggressive or defensive sounds they make, or from media portrayals that anthropomorphize animal behavior. While rats can produce sounds indicating agitation, these differ from a true growl.
What Sounds Do Rats Actually Make?
Rats produce a diverse range of sounds, many beyond human hearing. Their vocalizations include both audible and ultrasonic frequencies, each serving different purposes.
Squeaks
Squeaks are recognizable rat sounds audible to humans. These high-pitched noises convey messages from mild protest to distress or pain. A soft, low-pitched squeak may indicate contentment, while a loud, shrill squeak or scream often signals fear, severe pain, or extreme distress.
Chirps
Chirps are another rat vocalization, often softer and more complex. These sounds signify happiness, excitement, or playfulness, particularly in young rats during interactions.
Bruxing and Chattering
Bruxing is the sound of a rat grinding its teeth, often indicating contentment or relaxation, similar to a cat purring. This behavior also helps rats wear down their continuously growing incisors. Chattering, a louder form of teeth grinding, can signal agitation, stress, or readiness for confrontation.
Hissing
Rats may also produce a hissing sound, a defensive display when they feel threatened or are in a territorial dispute. This sound acts as a warning to potential threats.
Ultrasonic Vocalizations (USVs)
Ultrasonic vocalizations (USVs) are a significant part of rat communication, occurring at frequencies between 20-100 kHz, above human hearing. These USVs are categorized by frequency and context. For instance, 22 kHz calls associate with negative emotional states like fear or distress. In contrast, 50 kHz calls indicate positive emotional states, such as during play, mating, or pleasurable social interactions.
The Purpose of Rat Vocalizations
Rat vocalizations serve various communicative functions within their social structures. They express emotions, signal warnings, and facilitate social interactions.
Emotional States
Different sounds communicate emotional states. Bruxing expresses contentment, while high-pitched squeaks and screams convey distress or fear. These audible signals allow other rats to assess the emotional condition of their companions.
Warnings and Alarms
Vocalizations also signal warnings or alarms. Hissing indicates a rat feels threatened, aiming to deter dangers. Ultrasonic alarm calls alert other rats to predators, prompting evasive action.
Social Interaction and Bonding
Social interaction and bonding rely on vocal communication. Ultrasonic vocalizations, particularly 50 kHz calls, are emitted during positive social activities like play, grooming, and mating, fostering group cohesion. These calls can also indicate dominance or submission, helping maintain social hierarchies and prevent aggression. Rat pups use specific vocalizations to communicate needs to their mothers, such as hunger or cold.