The Fly
Scholars have said that seeing a fly enter one's stomach may indicate mixing with base and despicable people, possibly gaining unlawful and fleeting money from them. A large number of flies in a dream is interpreted as a harmful enemy. For a traveler, flies landing on their head might forewarn of highway robbers who will steal their money, and citing a Quranic verse, flies landing on one's possessions may signify fear of thieves. It was also said that killing a fly signifies comfort and good health.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam