Hens killed and ate other hens

[ljump]

I awoke this morning to three dead hens in my run--killed and eaten by my other three hens.

The question I have is if I should cull the hens that are left.

Here is the situation: The three that were killed were 7 months old and the others are 2 years old. They all had been co-mingling in one large 20'x20' run over the last month with two hen houses to go between. The younger girls had been in an adjoining run the previous months so everyone "got to know" each other before I opened up the gate between the two runs. Everyone had seemed to figure out their place--no pecking was happening and there was some chasing here and there--normal behavior.

What was different: Yesterday I had decided to do spring cleaning on the smaller girl's run and didn't get finish and left it closed overnight--keeping everyone in the larger run together without the possibility of going back and forth between the two runs.

I am wondering if a turf war broke out overnight and the older girls didn't like being "forced" to share their space. That being said, I have two 3-week-old chicks inside the house that I am now reconsidering intermixing with the older girls now at any time.

I feel absolutely terrible about this happening, thinking it was preventible, but at the same time understanding chickens do what chickens do. Do I cull the three in order to try and prevent this happening to my future hens?

Any advice would be appreciated!

 

[MjChickens]

What is the breed of the older ones?

 

[patman75]

I'm guessing a predator killed the chickens and the other ones were picking at the dead ones.

 

[columbiacritter]

You sure it wasn't something else that killed them and the older hens just took advantage of the snacks? Chickens will kill each other and they they seem to consider chicken as the best eats around. After that amount of time together I wouldn't have thought they'd kill all three at once.

I usually don't let new birds in wth th eadults until they are nearly full grown and able to defend themselves.

 

[ljump]

The older hens are 2 Buff Orps and one California Grey. The younger girls were Silkie, Black Cochin, and a Blue Andulsian. The two runs are fully enclosed and locked--I looked for an external predator entrance or evidence a cat, raccoon or something else was in there and couldn't see anything unusual.

 

[MjChickens]

So were the younger ones found in the coop or out in the run?

 

[ljump]

They were found in the enclosed run pretty close together--eviscerated and heads pecked.

 

[MjChickens]

I think you may have a predator. I can't see the others going out of their way to attack them. The younger ones were most likely confused and didn't know where to go in for the night. Is the top of the run covered?

 

[MetalSmitten]

i also think you probably had a predator... chickens sleep at night, not attack each other, they can barely even see in the dark. the older hens probably were territorial about their roosts, so the younger hens probably stayed outside and got attacked by something else. in the morning, the older hens took advantage. =/ my guess, anyway.

 

[ljump]

Thanks everyone for their comments. I'll look closer for a predator entrance.