Hen suddenly roosting on top of nest boxes

[Jrobb78]

I currently have 3 chickens, all around 2 years old, one of which just hatched 3 chicks. Around the time the eggs hatched, one of the others, a RIR, suddenly started roosting on top of the nest boxes. Any idea why this could be? The new mom and babies are in a milk crate nest below the nest boxes. They are in with the other chickens, I don’t have them confined, so they are around each other all day. I’m stumped.

 

[Jrobb78]

Also, the boxes aren’t covered, so she is perching on the edge a piece of plywood! It can’t be more comfortable than the roost.

 

[aart]

Also, the boxes aren’t covered, so she is perching on the edge a piece of plywood! It can’t be more comfortable than the roost.

Is it higher than the roost?
Best to have nests covered with a sharply slanted 'roof'.

 

[Jrobb78]

No, the roost is higher.