The humble coconut may hold the key to controlling the spread of malaria—which kills about 2.7 million people each year—without the use of toxic chemicals. E Magazine (Jan./Feb. 2001) reports that Peruvian scientist Palmira Ventosilla has found that coconuts are the ideal incubators for a spore-forming bacterium called Bt (Bacillus/Thuringiensis) that kills the mosquitoes that carry the disease. A cotton swab containing Bt is placed in a split coconut and allowed to ferment for a couple of days. Then the coconut is opened and left in mosquito-breeding ponds. The insect larvae eat the Bt, which is lethal to them, but safe for the environment.