Are these chicks too old to introduce to a broody hen?
It honestly depends on the hen and the chicks. How long has the hen been broody? The only time it hasn't worked for me is when the hen had only been broody for a short time. I think anything is worth a try once. If it doesn't work out just place them back in the brooder. My only worry with older chicks is that they wouldn't imprint on mom. If it's cool out I think they may be more inclined to snuggle under her though.