Those who feel that the world is going a little batty over airport security measures may actually be right. A new surveillance system could eventually replace the standard metal detectors. Called Tadar after the Brazilian bat Tadarida brasiliensis, it uses millimeter waves to locate objects concealed under clothing. The technology, adapted from systems developed for navigation in European Space Agency spacecraft, is modeled on echolocation — the way that bats bounce high-frequency pulses off objects to orient themselves and find insect prey. The Tadar screening device, made by Farran Technology Ltd. of Ballincollig, Ireland, uses harmless 3-mm wavelengths that reflect from objects that block the body’s natural radiation. Thus, it is useful for discovering not only metal weapons, but also nonmetallic materials, such as plastic explosives, that a metal detector would miss. The scanning mechanism can refresh the image 10 times per second, allowing walk-by screening, and because it can produce three-dimensional images of a scene even at a distance of 50 m, it can be used for stand-off surveillance. The system was introduced in October at the Inter Airport Europe Exhibition in Munich, Germany. Gosh, Batman, what’ll they think of next?