Henry’s Pocket – The Weird Flap Of Skin On Your Cat’s Ear

Have you ever been lovingly caressing your cat’s adorable head when your fingers have strayed upon something a little ‘off’ on their ear? Right there, on the outer edge, it kind of looks like an extra flap of skin, or even a tear. Has your cat injured themselves? Are they growing themselves an extra ear? Nope, that’s Henry’s Pocket.

What is Henry’s Pocket?

Erm, what now? “Henry’s Pocket, more scientifically called a ‘cutaneous marginal pouch’, is a small flap of skin at the base of the outer edge of a cat's ears,” Dr Bozena Zaleska, lecturer in animal health at Hartpury University tells The Wildest. If you follow your cat’s ear from the point at the top, down the outer side, you should find it: an extra flap of skin that creates a kind of pouch or ‘pocket’ on their ear. “It’s also present in other mammals like dogs, bats, Mustela family – like weasels and stouts – as well as others,” says Dr Zaleska.

Why do cats have Henry’s Pocket?

OK so, totally normal then. But, what is it for? Not much, as far as we know. “There is no scientific evidence on what it really does,” explains Dr Zaleska. “But there is speculation that it does increase the range of hearing and amplify the sounds.”

Cats have one of the broadest ranges of hearing among mammals, on the low end, they can hear about the same level of sound as us but on the other end, they can hear much higher-pitched sounds, up to 85 kHz (humans can hear up to 20 kHz). Keep that in mind next time they give you a disdainful look for singing Taylor Swift into your hairbrush.

A cat’s outer ear flaps (pinna) are shaped to capture sound waves and funnel them through the ear canal to the eardrum. They can also independently point backwards as well as forwards and sideways to pinpoint the source of a sound. It’s been speculated that Henry’s Pocket could help with this movement.

Is Henry’s Pocket dangerous?

Nope! It doesn’t mean your cat’s been fighting or caught their ear somewhere and it is totally normal. However, Dr Zaleska does warn that because the skin is so thin there is a slightly higher risk that it could get damaged during a fight. It might also be a place where ear mites may gather if your cat is afflicted. It’s probably worth paying attention when doing your regular clean.

Where did the name Henry’s Pocket come from?

Here’s the kicker: no one knows exactly who Henry is. According to Dr Zaleska: “It’s been suggested that it comes from Joseph Henry who studied electromagnetism and sound waves, so it might be a nice way to honour him.”

Here’s hoping Joseph Henry found an extra flap of kitty skin a fitting tribute.