Just as humans see the world through minute eye movements, pigeons stabilize their visual surroundings by moving their heads and letting their bodies catch up.

Pigeons often look like they’re bobbing their heads as they walk, but it’s their way of seeing that’s plays tricks on our own eyes.

The birds move their heads forward so that for about 20 milliseconds, the external world becomes stable and their eyes can adjust to the surroundings.

This is similar to the way humans orient themselves with constant, tiny movements of the eye except it is easier for birds to use their flexible necks.

There is no backward head motion; that is an optical illusion.

The head shifts then stays stationary as the body catches up and moves past it.

In 1978, a Canadian researcher conducted a series of tests on pigeons, one of which was recording their body movements as they walked on a treadmill.

The birds’ heads did not “bob” since the visual surroundings stayed the same even as the body moved.

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