Do horse stallions kill foals that aren't theirs?

Yes, horse stallions may kill foals that are not theirs, particularly if they perceive them as a threat to their own reproductive success. This behavior, known as infanticide, is more common when a new stallion takes over a harem or group of mares. By eliminating unrelated foals, the stallion encourages the mares to become receptive to mating sooner, ensuring the propagation of his own genes. However, this behavior is not universal and can vary among individual stallions and circumstances.