Has anyone used these for their ducks for years with no problems of them eating them or getting sick from them? I would hate to used them and it end up killing my daughters ducks. I'm pretty excited about them because it sounds like they absorb so well and will reduce time spent cleaning up. I'm cleaning the straw twice a day. And I'm dealing with small pencil lead sized sores on one of my ducks feet. Im hoping that they wouldn't eat any remaining chunks.