Insecticide-treated bed nets are considered our most-effective weapon against malaria, responsible for 68 percent of the reduction in malaria cases across the world since 2000. In countries where the disease is common, an estimated 80 percent of people with a net slept under it last night.

The Johns Hopkins Center for Communication Programs’ VectorWorks project not only helps distribute nets across wide swaths of sub-Saharan Africa. VectorWorks, funded by the President’s Malaria Initiative (PMI), also works to understand how long treated bed nets last — and how they can keep malaria-carrying mosquitoes away longer. This is the story of “Net Detectives” in Tanzania, whose job it is to monitor nets for durability and effectiveness while looking for clues on how to make a good malaria-prevention tool even better.