Adults live 10 to 15 days. The longnosed cattle louse has a slender, pointed head and a narrow bluish black body. It is more commonly seen on calves and dairy stock and rarely occurs in large numbers on mature animals. This louse is usually most abundant on the dewlap and shoulders but will spread over the entire body when animals become heavily infested. As the weather warms in the spring, and numbers drop, they are usually seen last on the shoulders.
Females deposit an egg a day during their life.
The complete life cycle takes about 3 weeks. Little blue cattle lice are found most often in small clusters on the muzzle, neck, and dewlap of mature cattle. Clusters of lice around the eyes cause heavily infested animals to look as if they are wearing glasses. Females lay one to two eggs a day and the hair to which an egg is attached is typically bent at an angle. The eggs hatch in about 10 days and the nymphal stages require about 11 days.