A family of insects (order Blattaria) consisting of over 4000 species of cockroaches, largely tropic but worldwide in distribution, including a number of abundant pests of households, kitchens, and institutions or facilities, wherever food is present; noxious wherever found, yet not positively incriminated in natural transmission of pathogenic organisms to man. Common household pests include the German cockroach, Blattella germanica, the American cockroach, Periplaneta americana, and the oriental cockroach, Blatta orientalis. [L. blatta, cockroach]