How cats see, hear and smell

Cats see well in dim light, hear far higher sounds than people do and smell with great sensitivity. They see colour less richly than we do and cannot focus on things right under their nose. Knowing how your cat senses the world helps you avoid frightening it, choose better toys and notice when something has changed.

Sight

A cat's eyes are built for hunting at dawn and dusk. Cats are crepuscular, most active in low light, and their eyes show it.

• Big eyes and a wide pupil. The pupil is a vertical slit in bright light and opens very wide in the dark. This lets in a lot of light.
• A light-reflecting layer. Behind the retina sits the tapetum lucidum, a mirror-like layer that bounces light back through the retina for a second chance to be detected. It is why a cat's eyes glow in a car's headlights or a torch beam. A cat needs far less light than a person to see.
• Wide view, good with movement. A cat's field of view is wider than ours. It is very good at spotting small, quick movements, such as a mouse or a dangled toy.
• Colour. Cats see a narrower range of colour than most people. They see blues and greens and yellows reasonably well, and reds and pinks look duller. This is why toy colour matters less than movement.
• Detail. A cat's sharpness is lower than a human's. Objects far away look softer to a cat.
• Close focus. A cat has trouble focusing on things very near its face. That is one reason it uses its whiskers to check items at close range.
• A third eyelid. Cats have a third eyelid at the inner corner of each eye. You usually see it only when the cat is drowsy, unwell or relaxed. If it stays visible, ask your vet.

What this means at home

• Do not use a bright flash or a laser pointer in a cat's face. Finish a laser game by landing the dot on a real toy or treat, so the chase has an end.
• Make toys move. A wand toy or a ball that rolls is more interesting than a still toy.
• Keep a night light off if your cat sleeps. Cats do not need one. They may need a clear path, so keep furniture where it was if your cat is older or has poor sight.

Hearing

Cat hearing reaches much higher than ours. Cats can hear very high-pitched sounds that people cannot, including the squeaks of small prey. They also hear faint sounds from far away.

• Mobile ears. Cat ears swivel independently, so a cat can aim each ear at a different sound. Many small muscles move the ear.
• Location. Cats can pinpoint where a sound comes from quickly, which helps with hunting.
• Sensitivity to noise. Vacuum cleaners, fireworks, loud music and shouting can frighten a cat. High-pitched whines from some electronic devices may disturb a cat, though you cannot hear them.

What this means at home

• Give your cat a quiet room to retreat to when you vacuum or have guests.
• Speak softly. Cats often respond better to a gentle voice than a loud one.
• Be careful with ultrasonic gadgets and some appliances. If your cat acts bothered by a device, move or stop it.
• Cats that are white and have blue eyes may be born deaf or hard of hearing. This is linked to a gene for coat colour. A deaf cat can live well indoors, and a vet can test hearing.
• Older cats often lose hearing. Signs include not coming when called and loud meowing at night.

Smell and taste

A cat's nose is far more sensitive than a human's. Smell tells a cat who has been in the room, whether food is fresh and where its territory ends. Cats also use smell to mark territory and to recognise each other and you.

• The nose. Cats have many more smell receptors than people. A cat with a blocked nose often stops eating, since food that does not smell right is not eaten.
• A second smell organ. The vomeronasal organ sits above the roof of the mouth. It detects chemical signals, including pheromones. When a cat curls its upper lip and holds its mouth slightly open, with a faraway look, this is the flehmen response. It helps move scent to that organ.
• Rubbing and scratching. Cats leave scent from glands on the cheeks, chin, paws and flanks. When your cat rubs its face on you or on a door frame, it is placing a calming scent, and it is claiming you as part of its group.
• Taste. Cats have fewer taste buds than people and cannot taste sweetness in the way we do. They respond strongly to savoury, meaty tastes and to smell.

What this means at home

• Strong smells can stress a cat. Many essential oils, scented candles and cleaning products can irritate or harm cats. Some essential oils are toxic to cats. Ask your vet before using diffusers or sprays.
• Warm food can smell stronger. A cat that eats little may eat more when its food is warmed slightly. If appetite is poor for a day, call your vet.
• A new cat or a visitor brings new scents. Introduce them slowly.
• Wash a place where your cat has urinated outside the litter box with a cleaner your vet recommends. Some cleaners leave a scent that draws the cat back.

Touch and whiskers

The whiskers and the paws are rich in nerve endings. Whiskers sense air movement and nearby objects, which helps a cat judge gaps and find things close to its face. Never trim them.

When senses change: see a vet

Changes in vision, hearing or smell can be a sign of illness. See a vet soon if you notice:

• the cat bumping into furniture, missing jumps or seeming confused in the dark
• cloudy eyes, one pupil bigger than the other, or eyes that stay wide open in normal light
• redness, discharge, squinting or pawing at an eye
• head shaking, scratching at the ears, smell from the ears, or not responding to sounds
• a cat that stops eating because it cannot smell its food
• circling, a head tilt or loss of balance

Go to a vet now if your cat:

• suddenly seems blind or has very large pupils and acts disoriented
• has an eye injury
• breathes with an open mouth or struggles to breathe
• has not eaten for a day or more
• strains in the litter box or passes little or no urine, especially a male

Sudden blindness can come from high blood pressure and other serious conditions, and it needs prompt veterinary care.

Common mistakes

• Using lasers without an ending. Cats can become frustrated.
• Assuming a cat sees like us. Move toys, and ignore colour.
• Shouting at a cat. Loud voices are harsh to cat ears.
• Cleaning with strong scented products. They can irritate or harm.
• Ignoring changes in sight or hearing. They can signal disease.
• Trimming whiskers. They are sensory organs.

Summary

• Cats see well in low light but less sharply and with less colour than people.
• Their ears hear very high sounds and can move separately.
• Their noses are far more sensitive than ours, with a second scent organ.
• Use moving toys, gentle voices and mild scents.
• Ask your vet about sudden or gradual changes in sight, hearing or appetite.