4 out of 5 of my dogs eat mud all day every day. I feed Hund-N-Flocken and Kirkland Super premium, occasional eggs, raw bones, mackerel, etc. As soon as I let them outside though, they all start devouring mud! The routine is always the same, dig a little, eat a little, dig a little, etc. Every time we go outside they do it. They don't seem to do it anywhere but my backyard, and only a certain area of my yard (weird, I know) I thought maybe it was grease from the turkey frier that had spilled out but it's just too far away from that area to be that. It doesn't make them sick or anything but I have to wipe off/out their mouths when they come in. Could they be lacking something in their diet and they're craving? Could they all just be insane? And also could this lead to any health problems? 3 of them are on Interceptor and 2 on Sentinel, they are all fully vaxed as well.