Why, oh why

I’ve been cleaning the stock tank every two or three days, since Hap, at least, has the messy habit of rinsing his hay before he eats it. I am used to finding wads and strands of hay in the water. However, this morning I could have sworn that I found mud in the bottom of the stock tank which I had cleaned, rinsed and refilled two days earlier. Are Hap, Rags and Smoke now using their stock tank to make mud pies?