During the Second World War Philip Callahan. a young entomologist, noticed a similarity in the behaviour of male moths seeking a partner. and of aircraft flying in and out of a homing radio beam. From that observation,
Dr Callahan, who works: at the United States De- partment of Agriculture : in Gainsville, Florida, has built a theory that he ' believes can explain many aspects of insect behaviour - including the old problem of why moths are attracted to candle flames. He talks to GEOFF WATTS about his ideas. Producer GEOFF DEEHAN