I have 5 Isa Brown chickens and am wondering when they will begin laying eggs. They are 15 weeks old, adorable, but I'm not sure if I should get the nesting box ready yet. They WERE sleeping and pooping in the nesting boxes so I covered them so they would not use them yet. Also, am wondering who out there HAS Isa Browns? They are a cross between a Rhode Island Red (mother) and a Rhode Island White (father). They are so cute. Getting chickens has been on my "bucket list" most of my life! They are so entertaining to watch. Thanks for the help.