Dawn is here.
On a Costa Rican beach in the early morning.
Gently sloping beach.
Wavetops, windswept, mist the air.
Suave swells sweep soft sand.
In the sand you may find the doorways to creatures’ homes.
These doors are sprinkled ’round with small balls of sand.
Notice a pattern here?
A scrape in the sand.
And a ball of sand
Scrape after scrape, ball after ball.
All along the beach are millions of scrapes, millions of balls.
Every scrape was made by the sweep of a small crabs claw.
Every scrape makes a ball of sand.
The crab then carefully nibbles over the grains of sand in the ball, removing the algae that grows on the surface of the grains.
When the nibbling is done, the ball of cleaned sand is put down, the crab moves along a bit, and scrapes and sweeps again.
Until the tide comes back in.
When the tide turns and the waves come in, the crab will go back into its burrow.
With a bubble of air to breathe, it will wait until the ebb of tide.
When it will dig itself back out to a freshly washed expanse of sand.
Then the crab will scrape and sweep and eat.