This reminds me of a talk I had with my dad, an equine veterinarian for 40 years. I'd seen that video of a horse eating a chick online and someone in the comments explained that horses are naturally opportunistic eaters and that's why it took the chance to munch it down. I confidently told him this later on and he said, 'nah, they're just stupid'.

If you throw a blanket over a horses head, it will think it’s dead and starve to death if you don’t remove the blanket

Someone on youtube said it therefore it must be true. I believe it.