moult

1. V-I When an animal or bird moults, it gradually loses its coat or feathers so that a new coat or feathers can grow. 脫毛; 換羽

Like most aquatic insects, mayflies moult as they grow. 像大多數(shù)水生崑蟲(chóng)一樣，蜉蝣在成長(zhǎng)過(guò)程中換羽。