You don't need to wait, you just need to give it time with them being able to see each other without being able to touch each other. I integrated 6 week old chicks into my flock(see link in post #6) and within 2 weeks everyone was good. They are now 14 weeks old and graze, roost, and dust bath with my older ladies. @U_Stormcrow also gave you some great reads on how to accomplish this.In that case I’ll have to wait until 3-4 months right?