my chicken stopped laying after predator attack

[alsaulnier]

A predator killed one of my free range chicken in September. My other hens stopped laying immediately. Two of them have started laying again the other six have not. I don't know what to do about it.

 

[Al Gerhart]

Chickens live on the razors edge between health and disaster. Everything that happens might interrupt their laying schedule or put them into a downward spiral. This is why one ALWAYS quarantines incoming new birds for a few weeks because the change in location and stress of travel will drop their resistance enough for disease already in their bodies but held in check by their immune system to kick in.

Chickens are prey animals so they reproduce fast and evolution has not wasted a lot of sturdiness in their bodies.