We rescued 3 girls that are estimated at ~6mo old. They only just started on layer feed (with us) and have oyster shells as free choice. They're sleeping in their roosting box/nesting box but so far haven't seemed to lay yet. Basically I'm wanting to avoid having them start laying randomly in the yard under a bush or something... They never had experienced hens around them and this is my first go with young chickens. Do I get a fake egg and put it in the nesting box? Do I wait for them to start laying first? Thanks!