Yes, you read that right. Brazil is intentionally releasing thousands of mosquitoes on its population. It turns out that these “good” mosquitoes have a bacteria that suppresses dengue fever. The government believes the mosquitoes will breed and multiply, hopefully becoming a majority of the population—which will therefore reduce the disease’s prevalence. The bacteria, Wolbachia, can’t be introduced to humans. A total of 10,000 mosquitoes will be released each month for four months just north of Rio.