Nesting Boxes - How soon?

[shamgar1]

My chicks are 4 weeks old and moved to the coop. (We are having very warm weather). I don't have any nesting boxes built yet. When do they need to be added?

 

[Nicole01]

Around 4 months or so. My girls laid at 5-8 months of age. I hear some breeds actually lay at 4-4.5 months.