A dog can smell a single grain of salt dissolved in a bathtub of water. They track people by the smell of their footprints. A bloodhound can smell things about 1,000,000 times better than a human.
Dogs detect their prey through smell. Their sense of smell is very acute. A dog's sense of smell is 10,000 - 100,000 more powerful than a human's.
Pheromones.
Dogs have a good sense of smell and acute hearing.
By echolocation
prey
men and dogs cats and you
Yes, some dogs are trained to detect lung cancer in people.
yes dogs can detect lower or higher sounds than humans
Lemurs are prey to hawks, dogs, and humans.
Cancer is 1 illness pets can detect, as far as scientists know, only dogs can detect it.
Both
yes
By eyesight. Their primary diet is small insects - the detect the movement of insects that get close enough for them to catch.
By the smell of the explosive