Forming a group habit and "figuring things out" are not the same thing.
Any new layer is a bit confused as to what it all means. Occasionally one will lay outside a nest box, though in the coop. I had a new layer very recently lay outside the box. It went on for three consecutive eggs. Each time I saw her settling into a spot on the floor, I moved her into a nest box. By her fourth egg, she finally discovered how cozy and private and preferable and superior a nest box is to the floor.
But when you haven't intervened to encourage the new layer to lay in the proper place, it then becomes a habit. Habits and chickens are like a chocolate chip cookie habit in a human - painfully difficult to break. The only way to break a habit of feral egg laying is to coop up the hens and reduce their choices to the nest boxes, thereby forcing them into the new habit.
@FunClucks has an excellent point. The nests must be of proper size and height. A hen must have room to stand up in the nest as that is her final stance when laying the egg. Gravity helps her to get the egg out. Privacy and clean nest are also important. So is a comfortable temperature and ventilation. If the nest boxes are oven hot, no hen is going to prefer that to a cool spot under a shrub outside.
Any new layer is a bit confused as to what it all means. Occasionally one will lay outside a nest box, though in the coop. I had a new layer very recently lay outside the box. It went on for three consecutive eggs. Each time I saw her settling into a spot on the floor, I moved her into a nest box. By her fourth egg, she finally discovered how cozy and private and preferable and superior a nest box is to the floor.
But when you haven't intervened to encourage the new layer to lay in the proper place, it then becomes a habit. Habits and chickens are like a chocolate chip cookie habit in a human - painfully difficult to break. The only way to break a habit of feral egg laying is to coop up the hens and reduce their choices to the nest boxes, thereby forcing them into the new habit.
@FunClucks has an excellent point. The nests must be of proper size and height. A hen must have room to stand up in the nest as that is her final stance when laying the egg. Gravity helps her to get the egg out. Privacy and clean nest are also important. So is a comfortable temperature and ventilation. If the nest boxes are oven hot, no hen is going to prefer that to a cool spot under a shrub outside.