Everyone hates mosquitoes. Besides the annoying buzzing and biting, mosquito-borne diseases like malaria kill over a million people each year (plus horses, dogs and cats). And over the past 100 million years, they’ve gotten good at their job — sucking up to three times their weight in blood, totally undetected. So shouldn’t we just get rid of them? Rose Eveleth shares why scientists aren’t sure. Lesson by Rose Eveleth, animation by Karrot Animation.