i was a young guy and out with a mate on new ground,he had a collie/hound and i had a bull/greyhound,we were knocking rabbits left right and centre,well after another retrieve my mate says''what the fcuk is that whisteling''and sure enough there was a low sound,the dog came in and we took the rabbit from him.i turned and flashed the lamp in the direction of the sound and we were no more than 4 feet from the edge of a cliff,100+foot drop over the edge.It was certain death if we had gone over.It was a quarry we never knew existed.I had another encounter with a Llama and my bull bitch,bloody rott