A cat purrs by sending rapid nerve signals to the muscles around the larynx, causing the vocal folds to open and close many times per second. As the cat breathes in and out, air passes the vibrating vocal folds, and it is precisely this movement that creates the low, steady humming sound. Because purring follows both inhalation and exhalation, it sounds almost uninterrupted, and this is the explanation for why a cat can purr for long stretches without taking a break. The signal itself is thought to come from a fixed rhythm in the cat's nervous system, which controls the muscles in the larynx in a fast, repeated pattern.

Purring therefore does not originate in the lungs or the chest, but in the larynx, where the airflow meets the tensed vocal folds. It is the same basic mechanism, whether the cat is curled up on the sofa or standing up rubbing against your legs. That is exactly why you can often feel the purr as a slight vibration through the cat's body long before you hear it clearly.

How the sound is created in the larynx

The larynx acts as a kind of valve between the throat and the windpipe. When the cat purrs, the small laryngeal muscles tense and relax at a very rapid pace, and each time they move, the airflow is briefly interrupted. This creates a series of small bursts of sound that lie so close together that the ear perceives them as one continuous hum. The frequency is low, typically somewhere in the deep register, and this is the reason why the purr feels more like a vibration than an actual tone.

The interesting thing is that the cat can purr both when it breathes in and out. For most other sounds a cat makes, such as meowing or hissing, the sound is only produced on the exhalation. Purring is an exception, and this is the explanation for its characteristic, almost engine-like continuity. Because the mechanism is involuntary and controlled by the nervous system, the cat can keep it going even while it relaxes completely or is about to fall asleep.

Why a cat purrs, and what it is trying to tell you

Most people associate purring with well-being, and that is often true. A cat lying relaxed in your lap with half-closed eyes, purring, is signalling safety and contentment. Kittens begin to purr very early in life, and already in the first weeks of life purring is a way of maintaining contact with the mother during nursing. That role carries on into adulthood, where purring continues to function as a social signal that all is peaceful.

But purring is not always a sign of pure enjoyment. Cats can also purr when they are stressed, unwell or nervous, for example at the vet's or in an unfamiliar situation. Here purring is seen as a form of self-soothing, a little like the way a person might hum to calm down. That is why it is important to read the purr in the context of the cat's other body language: ears, tail, eyes and the posture of the whole body. A cat that purrs relaxed with soft body language is telling you something completely different from a cat that purrs with a tense body and a darting gaze.

What the low frequency may mean for the cat

The low frequency of the purr has received a fair amount of attention, because deep vibrations in particular can, in theory, have a calming and possibly beneficial effect on the body. Some researchers have suggested that the low vibrations may play a role in the cat's ability to settle down and recover when it rests. However, this is an area where there is still more that we do not know than we know for certain, so it should be regarded as a possible explanation and not as an established fact. What we can say for certain is that purring is closely linked to situations where the cat is either feeling safe or trying to calm itself.

Regardless of the exact biological effect, purring is an important part of how your cat communicates with you. The better you get at reading when and how it purrs, the easier it is to understand whether the cat is thriving or whether something in its everyday life needs adjusting.

How to create the calm moments that make your cat purr

A cat that purrs contentedly is often a cat with a predictable and secure everyday life. Fixed routines around rest, play and meals bring calm to the system, and meals in particular play a big part in a cat's day. Many cats settle down completely and begin to purr around feeding time, because they associate the moment with something good. That is why the taste, texture and quality of what you serve can help make the daily moments something the cat looks forward to.

At ESSENTIAL FOODS all cat meals are premium and composed with human-grade ingredients and fresh raw materials, so your cat gets something it both enjoys and thrives on. In cat food you will find relevant products gathered with the cat's taste, nutritional profile and daily well-being in mind. If your cat prefers the soft, cooked texture, you can take a closer look at a meal like THE JAGUAR PÂTÉ, 12 PCS, where small, appetising portions make it easy to match the cat's appetite day by day. If your cat has started to get on in years, you may benefit from looking at meals for senior cats, which are composed for the everyday life of a cat with a few more years behind it.

When the purr doesn't match the situation

Because cats can also purr when they are having a hard time, it is worth paying attention if the purr appears in contexts that seem odd. A cat that suddenly purrs a lot while at the same time withdrawing, eating poorly, changing its behaviour or seeming unwell is not necessarily telling you that everything is fine. Here the purr is rather a signal that the cat is trying to calm itself, and that is worth taking seriously. If you find that your cat's behaviour or general condition is changing and you are worried about its health, it is always a vet you should contact for an assessment.

If, on the other hand, your doubts concern the feeding itself, that is, what and how much your cat should have, or how you switch between meals, ESSENTIAL FOODS' nutritional advisers are ready on the phone, chat and email. They can help you find the right choice for your particular cat's needs, so that the daily meals become one of the moments the cat settles down and purrs over. That way the purr becomes not just a cosy sound on the sofa, but also a small guideline for how your cat is actually doing.