Odd behavior

[JewelsJj]

I have a little Gold Lace Wyandotte who is 21-22 weeks old and she has just started laying eggs. She won’t use the nesting boxes but has built herself a nest in between our boxes and has pulled the straw out of the boxes and taking shavings from the coop floor and puts them on her back. I first thought she was doing it to just build her spot but she walks around, away from the nest and continues to pick up shavings and placing them on her back. Any ideas as to why? Has anyone seen this before?

 

[sourland]

It's a relatively common behavior. Perhaps a long ago trait when chickens covered their nest after laying?