Agressive chicks!!

[Ch1ckens]

Hey!
So I have 4 three week old chicks of all different breeds. A barred rock, buff brahma, buff orphington, and an americana. Lately I've been hearing so much noise from their brooder. Not like a sweet chirping noise, more like some sharp noises and lot of flying around noises. When I look in their brooder there all chasing after one another and jumping on echother. They were never this way!! It is mainly my americana that is doing this, she is a little bit bigger then the others and I think she might be a rooster. Why are they behaving this way?? What can I do to stop it?!

 

[scratch'n'peck]

Even my pullets would chase and posture when they were chicks. Hopefully they are not hurting each other.

 

[questions543]

Do you have a red brooder light? this will help ALOT. They should have enough space. Constantly good cool clean water, constant access to food etc...