Chicks attacking each other, bleeding

[Kate23]

I have 12 chicks that are 3 weeks old. 3 of them have little bald spots on their chests with a little blood and one has blood around its tail. I've seen the other chicks pecking at them. I separated the injured ones. What is causing them to do this??

 

[keesmom]

What is their brooder setup like (dimensions, how hot, etc)? What breeds do you have?

 

[Kate23]

What is their brooder setup like (dimensions, how hot, etc)? What breeds do you have?

The brooder is 4ft by 4.5 ft. Theybhave been in this one for about a week. I have 3 Columbian Wyandottes, 3 Austra whites, and 6 French cucko marans. And I just noticed one are pecking their own feathers now too.

 

[keesmom]

Space looks good, and they aren't too hot. In that case what are you feeding them? And where is the brooder located?

 

[Kate23]

Space looks good, and they aren't too hot. In that case what are you feeding them? And where is the brooder located?

They have starter feed. And the brooder is in our garage and my husband plays music and uses a saw and some other tools sometimes. Maybe all the noise is stressing them out??? I already made my husband turn off the music and try to keep it quieter in there.