Stress your peppers by making them thirsty, and they will reward you with mouth-sizzling fire. Danise Coon, assistant director of the Chile Pepper Institute at New Mexico State University, recommends cutting the plants' water intake in half to increase pungency. If you normally water your peppers every three to four days, cut back to one good soak per week. Don't worry if the plants look wilted. The heat in chile peppers is a defense against hungry mammals. "Chiles become more pungent under stress because a survival mechanism kicks in. A mammal's digestive system will crush a seed, hindering the chiles' reproduction process," says Coon. "When a chile pepper plant is stressed, to survive it creates more capsaicin (the substance that gives heat) to deter mammals from eating the fruits." In the chiles' native South America, birds are primarily responsible for spreading chiles because their digestive systems do not harm the seeds. Birds lack the oral receptors to detect pungency and will happily eat even the hottest peppers