The Bloodhound is a large scent hound, originally bred for hunting deer, wild boar and, since the Middle Ages, for tracking people. Generally in training the handler must know exactly where the runner went, so that he does not encourage the hound when it is wrong, or 'correct' it when it is on the scent, but he should not be too ready with his corrections if the hound goes astray, or it may come to rely on him. He should give the hound time to realise its mistake and put itself right, if possible. As training progresses the handler learns to 'read' his hound's behaviour. The hound must trust its nose and the handler must trust the hound. From early hot trails on a familiar person, the young hound progresses to colder trails on the scents of strangers. Laughing Dog in Duck Hunt, a Nintendo video game.