When I was building my coop I talked to other people about how many nest boxes to use. Everyone I talked too regreted building so many because the chickens prefered only a few. I put 8 in my coop of 20 layers. They only use 4-5 a day like I was told but my question is why are my eggs always so dirty? I try to put new straw in a couple times a week but everyday my eggs are a mess and have to be washed. Do I need more boxes even though they are not using them all or what do I try different?