Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
A single louse in a dream is a gossiping woman who divides people. Killing it indicates victory over a bad woman.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
A louse indicates a weak enemy. Its bite indicates slander from an enemy.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
A louse is interpreted as a servant. Killing it indicates firing a servant.