A JAPANESE company has developed a device to discourage pigeons from perching on statues, temples and other buildings and control the menace of pigeon droppings. Called a "bird stopper", the device works on a recent discovery that the homing characteristics of pigeons are influenced by the earth's magnetic field (New Technology Japan, Vol 2 1, No 9).

Pigeons have magnetic iron oxide, known to the ancient Greeks as lodestone, in their heads, which works like a biological magnet. The device produces a magnetic field that confuses the pigeons and keeps them away without harming them, the Japanese scientists say.