This is a true story.
about 18yrs ago on my usual mooch about on old waste land in the midlands,my old drawing dog was in front as he always was nosing about,he was 30ish feet in front of me and stopped dead in his tracks,watching him i stopped ,his head turning side to side as if listening for something.
Now i was expecting something to rise out the grass or him lunge forward for what ever was there.
what happened was just life saving for me the old dog edged back a few feet then some more till there was about 10 foot parting us,he started growling which to me was strange cause i couldn't