But there's all sorts of animal behavior we can't explain at all. Could some of this be due to reactions to environmental triggers that we aren't aware of? The assumption (at least according to the nature programs I watched as a kid) is often that it's something internal to the animal. But what if it's entirely external?

There's radar for a start - extraordinary sense of smell (what info do dog's get from smelling other dogs' piss?) - hearing different frequencies - the navigation skills of homing pigeons and migratory birds - there's a whole other world of sensations that we don't get.

The other side is do we as humans have sensory abilities that we don't utilize properly? Intuition might be one - we know we have it but don't properly understand how it works.

I once knew someone who was likely schizophrenic but in Taiwanese culture she was considered a medium with the other side. Actually i felt this person was being used unscrupulously by relatives for this purpose without regard to her mental health - but maybe there's something in it.