Why Do Cats Sniff Each Other's Rear? Scent Greetings Explained
It looks undignified to us, but for cats it is perfectly polite. When two cats meet, they often touch noses, then one or both will investigate the other's rear. This ritual reveals a lot about how cats communicate, and why scent matters so much in their social world.
A world of scent
A cat's sense of smell is far more powerful than ours. Cats have tens of millions of scent receptors, and a special organ in the roof of the mouth, the vomeronasal organ, that detects pheromones. For cats, scent is language, carrying information that sight and sound cannot.
The greeting ritual
When cats meet and feel comfortable, the sequence is often:
- Nose to nose, a brief sniff.
- Sniff the cheeks and face, where scent glands are.
- Sniff the flanks and body.
- Sniff the rear and tail base, where the anal glands are.
This sequence may take a few seconds or longer. Cats that know each other well may skip some steps.
What the rear tells a cat
Cats have two anal glands, one on each side of the anus, that secrete a strongly scented fluid. The scent contains information such as:
- Identity, as each cat has a unique scent.
- Sex and reproductive status.
- Health and diet.
- Mood and stress.
- How recently the cat was in the area.
Sniffing allows a cat to recognize friends and strangers, and to size up the other cat.
Other scent signals
Cats also mark with scent in other ways.
- Cheek rubbing and head butts, which deposit facial pheromones. See why do cats headbutt you.
- Scratching, which leaves scent from paw glands. See how to choose a scratching post.
- Spraying, which marks territory. See why do cats spray.
- Urine and feces, which carry scent.
The rear presentation
You may see your cat lift its tail and show its rear to you. This is a greeting, and a sign of trust. Kittens do the same for their mother, who licks them to stimulate elimination. Do not take it personally.
Why people get sniffed
Cats may sniff your hands, face or shoes. They are collecting information about where you have been and who you have touched. Offering a finger for a sniff is a good way to greet a cat.
When sniffing leads to trouble
If one cat is unwelcoming, it may hiss, growl or swat. Respect these signals. See cat tail language and cat ear positions. Forced greetings can lead to fights. See aggression between cats.
Introducing new cats
Scent is the key to introductions. Swap bedding, and let cats smell each other under a door before they meet. Give them time. See how to introduce a new cat to your cat and setting up a multi-cat home.
Returning from the vet
A cat that returns from the vet smells different, and may be rejected by housemates. Rub a towel on each cat to blend scents, and keep them apart for a while. See how to separate fighting cats.
Anal gland health
Anal gland problems, such as impaction or infection, are less common in cats than dogs, but can happen. Signs include scooting, licking the rear, a strong odor or swelling. See a vet if you notice them. See worms in cats for other causes of scooting.
Kittens
Kittens learn scent greetings early. Positive social experiences help. See how to socialize a kitten.
Respecting boundaries
Some cats are shy about being sniffed, and walk away or hiss. Respect this, and do not force them to meet. Provide separate resources, and let them choose when to interact. If you have a cat that is aggressive when approached, talk to your vet or a behaviorist. In multi-cat homes, watch for repeated rejection, which may signal tension, and provide hiding places and vertical space. See setting up a multi-cat home.
Cats and other animals
Cats may sniff dogs and other pets in the same way, gathering information about identity and mood. Allow brief, supervised sniffing, and watch for signs of tension in either animal, such as stiff bodies, growling or hissing. Keep greetings short at first, then separate, and repeat. Reward calm behavior with treats. A dog that is too boisterous may frighten a cat, so keep the dog on a leash for early meetings. See how to introduce a kitten to a dog.
When to see a vet
See a vet if your cat scoots, has a swollen rear or a strong smell. Use the US vet directory to find a clinic.
Frequently asked questions
Why do cats sniff each other's butts?
It is a polite scent greeting that gives information about the other cat.
Do cats do it to people?
Sometimes they sniff hands and faces, which carry scent.
Is it a sign of aggression?
No, it is usually a friendly or curious greeting.
Why does my cat present its rear to me?
It may be a greeting or a sign of trust, like a tail-up display.
Sources and further reading
Behavior problems often have medical or emotional roots. These specialist bodies explain how professionals assess them.
- Ohio State Indoor Pet InitiativeResearch-based enrichment ideas for indoor cats and dogs.
- International Cat CareVeterinary-reviewed advice on feline health, behavior and welfare.
- ASPCA cat careEveryday care, behavior and safety basics for cats.
Tailwisp is independent and written under our editorial policy. Learn who we are, or browse all cat guides.