A Japanese zoo is trying to do the impossible -- improve the image of cockroaches, putting on an exhibition of one of the world's most hated insects. With a whopping -- and disgusting -- 4,000 species around the planet, the hardy creature can survive almost anywhere, but is most commonly encountered by city-dwellers in grubby corners of the kitchen, or roaming around the floor at night. Staff at Shunanshi Tokuyama Zoo in Yamaguchi, western Japan, say the cockroach gets a bad press, and actually performs a vital job. "They have such a negative image," a zoo spokeswoman told AFP. "But they're actually playing an important role in the food chain." Important, but not very pleasant-sounding: eating rotting carcasses and dead plants on forest floors. One highlight of the exhibition will be a five-way race among cockroaches, where visitors can watch the worryingly speedy bugs whizz down a track. If that's not entertainment enough -- hard to credit -- the zoo is offering the chance to get your hands on a Madagascar Hissing Cockroach, which can grow as long as 7 centimetres (two-and-a-half inches). No need to worry about this, though, assures the zoo -- Madagascar Hissing Cockroaches can't fly. But they can hiss. The exhibition has around 200 creatures from a total of 15 species on display, and is already proving popular, the spokeswoman said, adding 70 to 80 percent of visitors are stopping by. Source: AFP