>>454002No.
>>453998 was actually correct. Many animal species tend to share the most universal types of body language, such as the signs for fear and aggression. That said, except in a few exceptions (like humans and dogs, which evolved together to be emotionally comprehensible), it's really just the most broad and obvious actions that are communicable. For example, running away, fidgeting, and at the extreme end, high pitched screaming or whining, as well as defecating, all tend to be common things that fearful animals do. On the flip side of that, *not* running away when faced with another animal, approaching the other animal, charging the other animal, showing teeth and growling all tend to be things that aggressive animals do. With this shared body language, animals have been able to communicate just enough across species barriers in order to not die out over time.
There is no "sixth sense," or other unexplainable fantasy bullshit. Even the title of the youtube video cited in the OP, "we were hiking a trail when I sensed we were being stalked," is not proof of some paranormal sense. Rather, most people, especially when engaged in activities (these people were jogging, and likely being social with each other), are capable of paying attention to things outside of their focus, at a low level. Likely, these people were focusing on their breathing, or perhaps on a lively conversation. However, their ears picked up footsteps that were out of rhythm with their own, or else they perhaps saw a giant black shape in their peripheral vision, at which point, they shifted their attention from 2 feet in front of their noses to the black bear that was walking out of the forest. That thing was probably chasing them for quite a while, simply because they were running, and that's why it continued to chase them, almost playfully, during the video. Bottom line, they didn't have a sixth sense; they used their five senses and shifted their attention.