Feared and regarded as dirty, dangerous and diseased, if there is one creature that tops the list of people's most hated animal, it is the much-maligned rat. Yet in Tanzania, scientists have trained rats to detect patients with tuberculosis, but what makes a rat's sense of smell so good?
Subscribe to BBC Earth: http://www.youtube.com/subscription_center?add_user=BBCEarth
BBC Earth YouTube Channel: http://www.youtube.com/BBCEarth
BBC Earth Facebook http://www.facebook.com/bbcearth (ex-UK only)
BBC Earth Twitter http://www.twitter.com/bbcearth
Visit http://www.bbcearth.com for all the latest animal news and wildlife videos
This is a channel from BBC Worldwide who help fund new BBC programmes.