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Scientists discover how roaches evade danger WebPosted Wed Jun 14 15:34:59 2000 -- LONDON -- No amount of pesticides seems to get rid of them. Urban dwellers are well aware of the hardy cockroach's ability to sense danger and evade it. But now scientists at the NEC Research Institute in Princeton, New Jersey, think they've figured out how the near indestructible cockroach does it. The researchers say the insects sense danger by changes in air movements around them. Tiny hairs on their back appendages act as sensors to tell them when and where to run. The study shows how the roach can tell the difference between normal wind in everyday life and when it's being threatened. The cockroach's hairs are connected to neurons that meet on a bundle of nerves. The message carriers in the insect called interneurons send information about the wind telling the roach what to do. Researchers attached electrodes to the cockroach nerves to measure the response of the neurons to controlled and repeated stimuli, or wind. The study's authors built two computer-controlled miniature wind tunnels. The roaches were then placed in the middle. At the same time, the wind was measured with a fibre optic wind detector, according to researchers. The authors say they're not surprised by their findings. The roaches, they point out, have been evolving for more than 300 million years — a lot longer than humans. The study appears in the journal Nature. Copyright 2000 Canadian Broadcasting Corporation - All Rights Reserved janet paterson 53 now / 41 dx / 37 onset 613 256 8340 / PO Box 171 Almonte Ontario K0A 1A0 Canada visit my website "a new voice" at: "http://www.geocities.com/janet313/"