news Japanese researchers find wood-feeding cockroaches munch each other's wings when mating The Mainichi TOKYO -- Researchers in Japan have confirmed that pairs of wood-feeding cockroaches chow down on each other's wing when mating -- apparently the first time mutual cannibalism between mates has been observed in the natural world. Unilateral cannibalism among species such as praying mantises, whose females eat the males, has long been known. Wood-feeding cockroaches live inside rotting trees in forests in southwestern Japan's Kyushu region and other southern islands, and come out of the trees only during breeding season between April and July to find mates. The insects lay their eggs in tunnels they burrow into their trees, and both parents provide the baby cockroaches, or nymphs, a liquid food they produce from their mouths.