Which animal has a better sense of smell than a bloodhound?

Bears. People have 40 million smell receptors. A dog can have as many as 2 billion. But a bear’s sense of smell is seven times stronger than a bloodhound’s. They use their noses to find food, avoid danger, and locate mates. The killer whale is believed to have no sense of smell at all.

Source: http://www.webmd.com/a-to-z-guides/rm-quiz-sense-of-smell