>>714847625Animals are much smarter than many people think. Predators avoid preys for two major reason.
1. The risk of injury. Animals know that getting a bad injury is a death sentence. There is a video of a lion getting it's entire lower jaw remove because of a hippo
2. Illness. Some predators know that they are feared and any prey that see them will run away. However, some will recognize that if a prey is will to walk towards them with no fear, something is wrong and will not risk getting sick.