Cockatiel is not acting normal

by Sara
(Canada)

For the past week my cockatiel, Baron, has not flown, squaked or let me pet him, even tough he usually does.He normal sits on my shoulder or when i hold out my hand, he climbs on to it, but he is avoiding it and running away when i do.

His wings are not clipped, and he is 3 years old. He is usually a very playful bird, and will spend 1 hour or more outside his cage. He is still eating and drink. All he really does is sleep and puff out his feathers. I just want to know if he is going through a faze or if he is sick.