You can't hear it over the noise of London's traffic. But it's there. That faint, whining hum. Right under my feet, thousands of mosquitoes are dining on human blood.
To visit them, you have to go through a sliding glass door into the London School of Hygiene and Tropical Medicine. This school started as a hospital on the Thames River, where doctors treated sailors returning from faraway places with strange parasites.
Today, the building holds countless exotic diseases that you hope you'll never catch. The mosquitoes carry just a few of them, and their keeper is an entomologist named Dr.