Question: Why does my young gelding sniff hay and then pee on it?

Answer: Your gelding is performing natural elimination marking behavior. While most commonly seen in stallions, geldings and some mares will exhibit a series of behaviors including sniffing and otherwise examining something, such as a pile of hay, a particular patch of grass, a pile of manure, or a patch where another horse urinated, assume a position over top the area of interest, and then urinate or defecate over top. Stallions are notorious for creating “stud piles” along fencelines or other areas demarcating their “territory”.