I have 2 Blue Am pullets and 2 RIR's. The Blue Ams born in March, the RIR's are about a year old. The RIR's lay daily the Blue Ams have yet to lay any eggs. They eat the same food sleep on same roost and drink from same waterer. So why no eggs from the Blue Ams? The Blue Am rooster seems to like all 4 of them so what gives?