The Lure of the Manure

Why do horses seem so interested in sniffing piles of manure left by their pasturemates and strange horses? Researchers at the University of Regensburg in Germany studied the behavior of 35 horses, first to determine the social status of each animal and then to see how interested the horses were in sniffing their own manure and that of other equines. When presented with several manure piles, the horses spent the least time sniffing their own droppings but showed the most interest in manure left by horses that had been aggressive toward them. The interest was tied less to whether the droppings were from known or unknown horses. Each horse also spent the most time investigating the droppings of horses of its own sex. The researchers theorize that horses use odors as clues to which horses are dominant and which may be challenged for access to food, potential mates, and shady resting spots.