A detection dog or sniffer dog is a dog that is trained to use its senses to detect substances such as explosives, illegal drugs, wildlife scat, currency, blood, and contraband electronics such as illicit mobile phones. The sense most used by detection dogs is smell. Hunting dogs that search for game, and search dogs that work to find missing humans are generally not considered detection dogs. There is some overlap, as in the case of cadaver dogs, trained to search for human remains.