ARMY worms have invaded parts of east and central Africa, threatening food security in the region. Reports in the Kenyan capital of Nairobi say the worms, also known as moth caterpillars, have destroyed 6000 hectares of crops in Kenya, Uganda, Tanzania, Rwanda and Burundi since lastmonth. Governments in the five countries have urged farmers to report any army worms to the nearest agricultural station so that their farms can be sprayed with pesticides. The worms are a serious pest of cereal crops and grasses, which leave behind damages compared only with that caused by desert locusts.