Explanation:

Nests: While many species of squirrels around the world build nests in trees, known as dreys, some, like the ground squirrels, make burrows in the ground.

Storing food: Squirrels are known for their behavior of caching or storing food, especially nuts and seeds, in the ground for future use. This helps them have a food supply during seasons when food is scarce.

Diet: Squirrels are primarily herbivores, consuming a diet of plants, nuts, seeds, and fruits. However, they can occasionally eat small insects, making them omnivorous.

Thus, all three statements are correct.