To turn yolks green? The acorns are falling on the oak near the coop and they've decided that they love one specific type. The nuts are tiny and they're eating them green and whole (once they knock the cap off). They seem to enjoy their occasional windfall treat but mostly it's when I let them out that they go looking for these nuts. But now I'm worried that my first egg (any day here...) might be really unappetizing.