Two large nesting eggs with a wooden sphere inside.

Give the toy to your child and demonstrate how to put the eggs in the correct sequence I.e. sphere inside small egg with the largest egg on the outside. Your child will enjoy playing with the eggs putting them one inside the other. For infants and toddlers, parents can do the activity of removing the layers of the egg and again hiding the sphere repeatedly. The hiding and the revealing of the ball make the child understand that objects do exist even if they are not visible to the human eye.
**Parental guidance is required at all times.