Mosquitoes are relentless. They swarm, buzz, and bite, leaving behind itchy red welts. Some of them spread diseases, such as Zika and West Nile viruses. Although there are countless mosquito deterrents that promise to keep these pests at bay, quite a few don’t actually do anything to stop mosquitoes from biting.Whether you’re planning your first backyard get-together of the year or thinking ahead to a summer spent outdoors, don’t let mosquitoes ruin a good time. Here’s what doesn’t work — and what does.