To address the question of memory, she used hand-reared squirrels allowed out one at a time to bury nuts in an outdoor arena.

She also buried fresh nuts at random sites chosen from those other squirrels had used in the same week.

They thrive on the two walnut trees, and the place is full of baby walnut trees from where they have buried nuts.

There they bury nuts in the flower boxes.

"Or they might recognize the kinds of places they bury nuts," he said.

A red squirrel sat on a stump and stared at him, then went on burying nuts.

Red squirrels will be busy burying nuts for winter.

Squirrels bury nuts, hiding them, and they try to remember their locations later.

The squirrels buried nuts all over our garden, but forgot where half of them were.

Millions of trees in the world are accidentally planted by squirrels who bury nuts, and then forget where they hid them.