Propolis is a pliable, resinous mixture that honey bees (Apis mellifera) create by mixing a variety of plant resins, saliva, and beeswax and which they apply to interior surfaces of their hives, namely at points of comb attachment and to seal up cracks and crevices on the interior side of hive walls. Greater propolis production is connected with improved hive health, and a new study finds a few simple methods beekeepers can employ to stimulate increased propolis production. (Photo credit: Flickr/Ontario Beekeepers’ Association Tech Transfer Program, CC BY-NC-ND 2.0)