What age ?

[ChurpyChicken]

At what age and point do I let the chicks near the older hens? Last year I kept two house til they was the same size, but this year theres going to be too many chicks. There is one cochin cock, one cochin hen, 2 warren, 1 light sussex, 1 leghorn, 1 EE, 1 rhode island red and a cream legbar.. They are all quite small apart from the cochins. They are sleeping in an massive house (could fit easily 50 hens), all free range. I currently have the chicks with there mums in a run and small house.

 

[jerseygirl1]

I seperate them where they can see but not touch when they are about 8 weeks old

 

[Ridgerunner]

Might I suggest you read this thread.

Raise with flock? thread
https://www.backyardchickens.com/forum/viewtopic.php?id=215937&p=1

If Mama is still broody, she will most likely take care of any integration issues for her babies. That is one strong reason I favor letting a broody raise her chicks with the flock. I will not say you cannot have problems with this approach. There are risks both ways. But you seem to have a lot of room for Mama to work, so now while Mama will take care of the integration issues for them is my recommendation. Once they are on their own, they will have work out their pecking order issues, but they have to do that anyway and those are usually a lot less severe than integration issues.

Good luck!!!