Dogs are able to track and locate disaster victims using their amazing sense of smell. They have about 200 million scent receptors in their noses. We only have about 5 million. Dogs can sort out smell about 10,000 times better than we can. The longer the nose, the better it works. On the job, search and rescue dogs use two different search modes.  One is air scenting, which involves the dog holding its head up  as it works off lead. They will try to catch the victims scent in the air and follow it to the source.  The other method is ground tracking.  A ground tracking dog sniffs out a specific scent as it works on a lead with his handler.  Keep lots of dog treats on hand when training these dogs.