introducing new hens

[mrz hen]

I have 4 wyandotte hens 12 months old and
2 isa hens 8months old and
1 isa rooster 7months old

I want two more wyandotte hens
I have enough room for 12 chickens so room isn't the problem. My worry is that they will fight and my hens that are laying now will stress out and wont lay.
my question is how do i introduce new chicken's to the family without stress...!

 

[chicknmania]

New chickens should be quarantined anyway, for the first three weeks. You put them in a pen where they can hear and see the others. They get used to being there, and after quarantine is over, you can move the pen so that they can all socialize through the wire.