What killed my chick?

[AshleyThom]

This is obviously an impossible question, I’m just looking for opinions.
I woke up to one of my 5 day old (5 days since they were delivered) chicks dead.
I check on them several times a day and do a “butt check” to clean any manure that is stuck near the vent to minimize the possibility of pasty butt.
This particular chick was a bit of a bully. They’re all black Cochins and this chick would constantly bite the other chicks’ beaks and legs. Pull their legs. He was one of the strong chicks. Never any loose manure, good size, ate and drank well. I’m wondering if maybe the other chicks ganged up on him. What do you think?
I say he, but I really don’t know if it was male or female. They’re all supposed to be female, but you never know.

 

[sourland]

I doubt that the others 'ganged up' on him. How/where are they housed? Any possibility of a predator?

 

[AshleyThom]

I doubt that the others 'ganged up' on him. How/where are they housed? Any possibility of a predator?

No, they’re in a brooder in my home. Separate room from my cat/dog/kids. No one can get in there.