I have a chicken who has taken to eating a lot of grit lately, both granite that I offer, as well as lots of little stones that are in the sand in the covered run. She only eats Nutrena's Feather Fixer as her food, and gets 1-2 red seedless grapes per day and maybe a 1/2 T of raw shelled sunflower seeds as treats. She has been on this diet all winter here in Wisconsin. She hasn't lost weight and seems to act fine, but maybe once a day she'll have quite a runny poop with bits of green in it and sometimes just white and yellow liquid. This is usually in the first half of the day. Her other poops overnight and during the rest of the day seem fine, but some do have quite a bit of grit in them. She has the occasional normal cecal poop too. It's just strange that she's eating all this grift and also having this diarrhea once or twice a day. She is about 4 1/2 years old, and takes off the whole winter from laying. She is starting to vocalize more and her comb is getting a little more red, a sign that she might be getting ready to lay in a few weeks. Any thoughts on all this grit eating and occasional diarrhea?