Mosquitoes, ticks, fleas, flies, no-see-ums, bees, ants, spiders, caterpillars: these pesky party crashers make it impossible to relax and have fun in backyards. They distract and diminish the enjoyment of the outdoor experience, and it goes beyond mere unpleasantness. No one wants to be swarmed or bitten by hordes of insects. What's worse is that you are subjected to these pests' hazards to your health.