Just one chicken won't use the nesting boxes. Any ideas?

[kyckling66]

I have 6 chickens, all the roughly the same age (but different breeds) that started laying about 3 months ago. All but one lay their eggs in the nesting boxes. The one that won't use the boxes lays her eggs in the corner of the coop on the floor. She also sleeps on the floor and won't roost like the others. It's been like this for the entire time, and she appears healthy. Any ideas as to why?

 

[Masonicflock]

she is a

and they have different personalities. I have a few that won't roost on the poles but on the floor so don't worry bout it it's all normal. She has found a spot she is comfortable with so let her be since it may be a dark corner or a sunny corner (different tastes).