When to integrate chicks with big flock? - Small Flock

[dfgkfghggfasd]

I have a group of 12 chicks aged between ~3 and ~5 weeks old.
My big flock consists of 3 female chickens. They are fairly small:

At what age is it safe to integrate the little chicks with the big chickens?
I plan to enable them to come up to the little chicks pens sometime today or tomorrow so that they can socialize.

 

[oldhenlikesdogs]

I integrate at 4-8 weeks. When my chicks are done with extra heat.

 

[blackdog043]

I integrate at 3 - 4 weeks. I brood in my coop, using the mama heating pad. Here's a couple links, that might help you with integration.

https://www.backyardchickens.com/articles/my-coop-brooder-and-integration.74591/

https://www.backyardchickens.com/threads/integrating-chicks-into-flock-at-4-weeks-old.1159151/

 

[dfgkfghggfasd]

@blackdog043 I've been trying to think of a way to cheaply set up panic doors.

Cardboard, why didn't I think of this. Great article:
https://www.backyardchickens.com/articles/my-coop-brooder-and-integration.74591/

About what dimensions do you use for the panic doors?

 

[blackdog043]

About what dimensions do you use for the panic doors?

I never measured them, about 3 - 4" wide and 5" high.