Malaria still kills half a million people each year, and has been doing so for centuries. Then there's Dengue fever, West-Nile virus and Zika. I'd say the scale

Malaria still kills half a million people each year, and has been doing so for centuries. Then there's Dengue fever, West-Nile virus and Zika. I'd say the scales are tipped in favour of keeping around some of those mosquito-killing bats.