Older hens killing 11 week old chicks

[Yardraptor]

What is your set up? I use a pen for the chicks but it doesn’t allow the chicks to go vertical at all.

This is when I put them in the coop with the hens but the pen is their own space.

 

[Yardraptor]

This is key. Unlikely that would happen in only 3 days, especially with 11 week olds which are big enough to look more like a threat vs 11 day old chicks, which are less likely to be seen as a threat.

At minimum I'd give it 1-2 weeks. And if you don't already have ample clutter in the run, clutter it up (and if you do, move everything around to confuse things a bit before you release the younger birds).

Thanks. What kind of clutter do you use?

 

[rosemarythyme]

Thanks. What kind of clutter do you use?

https://www.backyardchickens.com/threads/a-cluttered-run.1323792/page-6#post-25037140 - This is mine but there's plenty of other clutter suggestions in the thread as well.

 

[WingItRanch]

What is your set up? I use a pen for the chicks but it doesn’t allow the chicks to go vertical at all.

I have the main coop/run and a smaller one right next to it. Here you can see my hens glaring through the fence:

Could you maybe fence off part of the run for the newbies?

 

[ChicnRitch]

I had them separated for 3 days. In the past that was long enough but that doesn’t seem to be the case this time.

I'm no expert - but I'm thinking the babies need more time. I am always so stressed out when it's time to integrate . I wait till the babies are at least 8 weeks old. And this year we expanded the coop so I was able to give the babies their own space separated by a temporary screen. They lived in that space for dang near 2 months...and even then, the older girls were trying to bully them...but with a lot of supervision and space with hiding spots for them to run to, they found there way! Maybe you can set them up again...just give it more time...I hate the thought of you loosing any of your babies