A sweet way to avoid the dentist? Microbiologists are developing a probiotic mint that uses dead bacteria to fight off cavities. Morgan Walker/NPR hide caption

itoggle caption Morgan Walker/NPR

Kids might be more satisfied if they get one good treat instead of one good treat and one lesser treat. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Is there an angel or a devil behind the mask? Scientists say it may not matter in terms of anonymous behavior. Joel Saget/AFP/Getty Images hide caption

itoggle caption Joel Saget/AFP/Getty Images