aggressive cockatiel

Question
QUESTION: I have a 5+ year old cockatiel that has suddenly become aggressive and resists any attempts of affection.  Much of his time is now spent on the bottom of his cage as well. What is wrong?

ANSWER: Hello Amanda and thank you for you post.
It sounds like your Cockatiel might be getting sick.  The fact that he is sitting at the bottom of his cage is a good indication of this.
Another idea is that your Cockatiel is a female and getting ready to lay eggs.  Females can lay eggs without a male present.  The eggs are just not fertile.
In either case, your bird should be seen by a Certified Avian or Exotic Animal Vet as soon as it is possible.  If your bird is sick, then the vet can hopefully catch and treat the illness before it gets too serious.  If it is a case of the bird laying eggs, you need to be sure that she is healthy enough to be able to do so safely, so seeing a vet is a win/win situation (and it could end up saving you money in the long run).

Good luck and God Bless.
Dianna

---------- FOLLOW-UP ----------

QUESTION: I always thought it was a boy because he does talk and I heard only males talk.  Another thing the bird is doing when on the bottom of cage is biting the plastic part of the cage.  when I tell him to stop he will clime back to the top then 2 sec later he is back at the bottom doing it again if you try to put your hand near him he will come after you.  He is still sleeping on his perch.

Answer
Hello again Amanda.
You heard right, female Cockatiels do not talk.  
Try getting some bird safe branches to put at the bottom of the cage, or some toys that can safely be at the bottom of the cage.  My oldest male Cockatiel will sometimes go to the bottom of his cage and chew on things also.  I have put a couple of toys at the bottom of his cage and he chews on them.
It sounds like your Cockatiel has really hit maturity (some birds do take longer than others, just like people do).
Do not put your hand into his cage, unless it is to change his food and water.  This is HIS safety zone, and he will go after anything or anybody that invades HIS territory.
He may be bored.  Is he getting out of his cage for at least an hour a day?  If not, he needs to.  This will help to break up the same old thing of stying behind bars all of the time.  Also, be sure that he has toys hanging from the top of his cage and rearrange them often.  This will also give him enough change that he won't be so bored.
Let me know how it goes.

God Bless.
Dianna