The favorite nesting box

[WMassforestflock]

OP Update: y'all are super helpful!

Lower height + dark painted interior + a fake egg in the disfavored box = equal use of both boxes. Thank you all!!

 

[aart]

equal use of both boxes

WooHoo!!

I hope that smaller one on the right is attached to the board behind it...so it won't fall.
...or maybe it's heavier and more stable than it looks

 

[WMassforestflock]

WooHoo!!

I hope that smaller one on the right is attached to the board behind it...so it won't fall.
...or maybe it's heavier and more stable than it looks

Yes, it's attached!!