A Type D personality is distressed, Type D's have a negative outlook towards life and are pessimistic. A small event that is not even noticed by type B can ruin type D's day. Type D personalities are more subject to depression than other personality types.
For most of human history, horses were seen as prey to be hunted for sustenance. During the late Pleistocene, around 55,000 years ago, Neanderthals scavenged off of horse carcasses and made occasional kills of their own.
Because hay is basically grass, and grass is what horses have evolved eating for thousands of years. It is natural for them to eat, and the best thing for them to eat. 1 person found this useful.