Pine Shavings =Clean eggs??

[Horse-n-bunny]

Although this is not all that important my mind is very inquisitive about everything chickens and so here goes: How come Eggs laid in a nesting box with a lot of fresh pine shavings are always super clean and eggs laid in nesting box with very little shavings have poop and other discoloration? is there a good technical reason?thank in advame for your help

 

[oldhenlikesdogs]

Perhaps the clean birds are using the clean boxes, and the dirty poopy birds are making the boxes dirty and disheveled. Some of my hens are just dirty, some seem a bit more concerned about their hygiene, and are cleaner, I have a couple that poop every time they lay an egg, hate when I reach in and I grab the poop with the egg.