If could be because it's scared if it's while you're trying to interact with it. If it's alone in the cage, it could be neutral or sleepy.
The top feathers on a cockatiel's head are known as the crest, not 'crown'. The usual position of a cockatiel's crest is down; this is when it is feeding normally, or not over-stimulated in some way. A cockatiel will raise its crest when it is alarmed or excited, so if the crest is down, it simply means that life is normal, and there is nothing for the bird to be particularly excited about.
Disrespect to gang.
should wood decks be installed crown down
Yes, cockatiels can get parasites.
I'm assuming you mean 'cockatiels,' the bird. :) But, no, they usually don't. Many cockatiels won't stop moving around and yelling, since they have no idea where they are.
Cockatiels are a type of cockatoo.
Cockatiels should not have a lump on their throat.
Cockatiels are parrots, and members of the cockatoofamily.
The phrase 'Corona Del Mar' translates from Spanish into English as 'Crown the Sea'. This is broken down as the following Corona = Crown, Del = the, and Mar = sea.
No, cockatiels should only be housed with other cockatiels. Not only do other types of birds have different types of diets, but they also have different personalities and will sometimes clash with cockatiels.
Answer: Sure, they can. When cockatiels are white, they are either of the Lutino breed, or they are albino.
62% of all cockatiels sold in stores are males.
If by this you mean why do cockatiels have crests then its because it frightens predators, larger birds and if it dislikes a person it may raise it to frighten him/her Cockatiels are small members of the cockatoo family. All cockatoos have crests. These birds may raise their crests when they are startled, or flatten them when they are angry.