APOPO is headquartered in Tanzania, though registered as a non-governmental organization in Belgium. The rats they train are larger than the kind that inhabit our cities. These are African giant pouched rats, and they deserve the honorific APOPO gives them: HeroRATs.
These smart creatures learn to sniff out landmines. Because they are so light, they can stand right on an explosive device without setting it off. They also learn to detect tuberculosis. They are far more adept at that than a laboratory.
The TED video below shows how the rats are trained and talks about some of the other possible ways in which their keen sense of smell makes them incredible allies. Bart Weetjens, who grew up loving rodents and Africa, tells the fascinating tale.
After wandering around on the APOPO site and watching this TED video, I will look at rats with far more admiration. They are clever, sociable creatures, and they are doing amazing humanitarian work.