Maximo Cardoso had never used a crossbow before, but he was intuitively able to assemble the Barnett Raptor FX, a model typically marketed for deer hunting. The field guide also displayed natural marksmanship. So it was agreed: He would be the one to launch the poison. At the base of a sheer rock face amid dry scrub in Bahia, Brazil, decked out ina beekeeping suit, Cardoso took aim at a 45- degree angle, the crossbow loaded with bolts modified to carry glass vials of insecticide. He was targeting small cavities in the red sandstone above that held nests of invasive Africanized honeybees. Depending on the size of the hive and difficulty of shot, it took anywhere from a single bolt to as many as nine for each of 52 hives. Two or three hits usually weakened a hive enough to allow the team's work to continue.