When can they go together?

[yoie]

I have two different hatches of coturnix quail, first group is 6 weeks old and the second group is 3 weeks old. When can I put the two groups together?

 

[TwoCrows]

I would wait until the 3 week olds turn 6 weeks old. Fully feathered and full sized. That way they have all the advantages of being the same size and mental growth as the adults.