Mosquito
> 2 million deaths annually
Even before “zika” became an everyday word, mosquitoes were already killing roughly two million people a year by spreading Malaria. These nuisances have been around for 400 million years, unfortunately, so if you’re hoping they might go extinct, don’t hold your breath. Mosquitoes are extremely efficient at detecting their next meals, using their senses to detect blood up to 35 meters away. They observe for human movement, they detect infra-red radiating from warm bodies, and are attracted to carbon dioxide and lactic acid using chemical receptors. They are more attracted to larger and more active humans due to the increase of carbon dioxide and lactic acid production.