Andy of How To Make Everything decided to make his own bug spray by growing certain plants and extracting their essential oils. He put the oils into alcohol that he distilled from some foul-smelling crabgrass beer he’d made previously. Then he went to a wildlife preserve with some friends to test out the spray. He deemed the spray to be “moderately effective,” but said he is going to order a batch of research mosquitoes and perform a more scientifically rigorous test in a couple of weeks.