According to a report in the New Scientist journal, scientists at the Hebrew University in Jerusalem filmed cockroaches in a circular enclosure, divided by a wall, using a high speed camera (recording 250 frames per second). They recorded the roaches running at speeds of three feet a second and making 25 twists and turns a second. Professor Jeff Camhi of the Hebrew University said, ``We know of no other animal capable of such a high frequency of body-turning.'' Flies and maggots swarming over food, dead animals or dustbins are things people associate with hot and dirty countries. But cockroaches are creatures which signal a lack of hygiene anywhere in the world. There are 3,500 species of cockroaches, ranging in size from a quarter of an inch tothree inches long, and they have been around on earth for some 400 million years.

Cockroaches have survived long exposures to X-rays, dunked in water are still likely to be alive after 10 minutes, and anyone who has tried to kill one knows the frustration of seeing it crawl away alive after being stepped on by a large boot. So, being the world's swiftest side-stepper is only one more trick in the roaches' survival manual.

Camhi, who has spent years in close proximity to cockroaches said: ``If the cockroach were not such a bad house guest, it would no doubt receive the admiration it richly deserves.'' He added, ``I don't admire him in my home, but I do in the lab his nervous system is really beautiful.'' What fascinated Camhi and other scientists studying cockroaches is their ability to change direction to avoid obstacles so quickly and so often. The creatures were filmed running along a straight wall. They kept a fixed distance from the wall using their antenna as a guide. They did the same when azigzag wall was used. Since cockroaches are largely nocturnal, the conclusion was that they could not be possibly using their eyes. In order to prove this, Camhi blindfolded his cockroaches with blobs of wax. This made no difference to their agility in avoiding the wall. So, it would have to be their antenna. The scientists immobilised the base of the cockroach's antenna with glue. This made no difference either. They then snapped off the tips of their antenna, and for the first time found that the cockroaches could not navigate and bumped into the wall.

For a cockroach to change direction an electrical impulse has to travel from the tip of its antennae into the brain and then to the legs. What continues to puzzle scientists is how the cockroach's antenna transmits signals to the brain so quickly, given that nerve cells in the antennae are very narrow and should therefore transmit information slowly. While Camhi and his ilk grapple with discovering the nervous secrets of cockroaches, the rest of the worldmay have discovered the best way to kill a cockroach. Go for the antenna!