What are the criteria for a toy that is most beneficial to a Cockatiel?

In order to choose the best toy for chicken parrots, several factors should be considered:

The material of the toy should be safe and will not cause harm to chicken parrots.

Toys should be able to meet the various natural needs of chicken parrots, such as digging, pecking, grinding claws and so on.

Toys should provide enough challenge and stimulation to help parrots use up excess energy.

The size of the toy should be suitable for the size of the chicken parrot, not too big or too small.

Toys should be changed frequently in case the chicken parrot gets bored.

Overall, when choosing a toy for a chicken parrot, you should consider the toy’s safety, ability to meet the chicken parrot’s natural needs, ability to provide enough stimulation, and proper size.