Sun and steps

The Ant in the Desert

With no trail to follow, how does an ant find a hole in the sand?

Generated interpretation

The Sun moves. A living compass has to keep time, or morning and afternoon will disagree.

Listen, or read

The words

A desert ant leaves the nest and hunts in a scribble. When she finds food, the path home is almost a straight line. She is not following her own footsteps. She is counting steps and reading the Sun, even the hidden pattern of light in the blue sky.

On salt pans and dunes, a desert ant leaves the nest and hunts in a scribble.

When she finds food, the path home is almost a straight line.

The sand holds little scent in the heat. She is not following her own footsteps back.

What we know

Evidence, held lightly

We know

Cataglyphis ants use path integration: a Sun compass plus a stride odometer.

They detect polarized skylight.

The evidence suggests

A time-compensated Sun compass keeps the heading as the Sun moves.

We are still figuring this out

How the brain stores the home vector so compactly.

Try this

A child can try this

Walk a scribble, then point home

In a yard or room, walk a wiggly path. Stop. Point back to where you started before you look. Then look. Your body was counting too, less precisely than an ant.

Also nearby

A question to carry outside

Could you notice direction without a street sign?