Rats do squeak at night, and the presence of these sounds when a house is quiet is a strong indication of rodent activity. Rats are primarily nocturnal creatures, meaning their most vigorous activity, including foraging, exploring, and communicating, happens under the cover of darkness. The quiet of the night amplifies the various sounds they make, from their movements to their vocalizations, making them much more noticeable to human occupants. While a rat’s audible squeak is not their main form of communication, hearing it suggests they are either in distress or engaged in a close interaction.
Rats’ Nocturnal Activity Cycles
The biological and behavioral drivers of rats are strongly aligned with a nocturnal lifestyle. These animals are primarily active from dusk until dawn, with peak activity often occurring just after sunset and before sunrise. This natural schedule is an evolutionary adaptation focused on avoiding predators, such as owls and other birds of prey.
The darkness provides a protective barrier, allowing them to carry out necessary activities like foraging for food and water. Their highly developed senses of smell, touch, and hearing allow them to navigate and explore effectively in low-light conditions. In human-inhabited environments, the nighttime also offers rats the advantage of reduced human activity and competition for resources.
If a rat is seen during the daytime, especially in a populated area, it can signal a very large infestation, high competition for resources, or an environmental disturbance. Their core circadian rhythm is centered around the evening and early morning hours, which is when most people will hear the resulting noises.
Decoding Rat Vocalizations
The squeaks you hear at night are generally a direct form of communication or a sign of physical distress. Rats use audible squeaks to convey surprise, protest, or pain, such as a sharp, high-pitched squeak when they are suddenly frightened or injured. They may also use a long, drawn-out squeak to indicate severe protest, often heard during aggressive encounters over food or territory between colony members.
A quieter, softer squeak might be part of socialization or a mild protest, often heard when one rat is grooming or playing with another. The meaning of the squeak is determined by its pitch and duration, with high-pitched, quick squeaks sometimes indicating a positive emotion or mild surprise, and lower, longer squeaks signaling unhappiness or fear. The majority of rat communication, including vocalizations associated with contentment and play, occurs in the ultrasonic range, which is inaudible to human ears.
The sounds humans hear are typically the more forceful, audible vocalizations used when rats are stressed, fighting, or in pain. If the noise is a repetitive, soft grinding sound, this is called bruxing and is made by grinding their continually growing incisor teeth. Bruxing usually signals a rat is content and relaxed, similar to a cat purring, though it can also be a sign of stress if accompanied by tense body language.
Identifying Rat Sounds vs. Other Pests
Distinguishing the noises made by rats from those of other common household pests like mice, squirrels, or raccoons relies heavily on the quality and volume of the sound. Rats are significantly larger and heavier than mice, and this difference is reflected in their movement sounds. Rat footfalls and scurrying sound louder, heavier, and sometimes like a slow, heavy thumping as they move through ceilings or wall voids.
In contrast, mice produce a lighter, higher-pitched scratching or pitter-patter sound due to their smaller size. The gnawing sounds also differ; rats have larger, stronger teeth, leaving coarser and bigger chew marks, which translates to a louder and more distinct gnawing sound than the lighter nibbling of a mouse.
Squirrels, which are often heard in attics, typically make a rolling sound, like marbles being scattered, and are more active around dawn and dusk compared to the deep-night activity of a rat. Raccoons are larger still, and their movement often sounds like a slow, heavy walk or thumps.