Chickens pecking each other

[Diedie]

I have 7 week old chicks. I keep them in the chicken run until they're bigger. But today I found one dead chick. They are fighting each other. Why? Need help please

 

[Happy Chooks]

Are they in with adults? If so, you may need to separate the 7 week old chicks until they are about the same size.

 

[Diedie]

All of them are 6/7 weeks old.

 

[Happy Chooks]

Are you sure it wasn't a predator?