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Sticky feet and a very fast eye

How Does a Fly Walk on the Ceiling?

A fly can land upside down on a ceiling, and it sees your hand coming long before it arrives.

Feet with claws andsticky padsEyes made of thousandsof tiny lensesTwo wings, and two tinystabilisersTaste buds on its feet
Almost nothing about a fly works the way you would guess.

  1. Step 1 of 5

    Its feet are hooks and glue.

    It stands upsidedown, quite calmly Hairs with a film of oilthat sticks

    Each foot has two claws for rough surfaces and two soft pads underneath. The pads are covered in tiny hairs that release a thin oily film, and that film holds the fly on smooth glass.

  2. Step 2 of 5

    It lands upside down on purpose.

    1 Flies uptowards theceiling2 Front feetreach up andgrab3 The body swingsover and up

    A fly does not fly upside down. It flies at the ceiling right way up, reaches up with its front feet at the last moment, grabs, and swings the rest of its body over.

  3. Step 3 of 5

    It sees the world in slow motion.

    You see About 60 pictures asecondA fly sees Several times more thanthat

    Your eyes refresh the picture about sixty times a second. A fly's does it several times faster — so your swatting hand looks slow and obvious to it, and it has plenty of time to leave.

  4. Step 4 of 5

    Its eye is thousands of eyes.

    Your eye One lens, sharp,pointing one wayA fly's eye Thousands of lenses,nearly all directions

    A fly's eye is a dome packed with thousands of tiny separate lenses, each pointing a slightly different way. It gives a blurry picture but covers almost every direction at once.

  5. Step 5 of 5

    It tastes with its feet.

    It lands onsomething Its feet taste itstraight away

    Taste hairs on the feet mean a fly knows whether it has landed on something edible the instant it touches down — which is why it keeps landing on your food, then walking about on it.

    The two little knobs behind a fly's wings are its back wings, shrunk into spinning weights. They work like a gyroscope and tell it which way up it is.

The short version

A fly holds on with claws and sticky pads, sees far faster than you, and tastes whatever its feet land on.

Try it yourself

Try to catch a fly by moving slowly instead of fast. Slow can work — it is the sudden movement its eyes are built to catch.

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