What is the ruling on minor blood from animals lacking flowing blood (e.g., fleas, lice, flies)?
Chapter on Praying with Impurity and Other Matters
Al-Mughni
Book of Prayer
Primary text
There are two narrations regarding the blood of animals without flowing blood (like fleas and lice). The apparent position is that their blood is pure. This view is supported by 'Ata, Tawus, Al-Hasan, Al-Sha'bi, Al-Hakam, Habib ibn Abi Thabit, Hammad, Al-Shafi'i, and Ishaq. The justification is that if it were impure, a small amount of water in which such an insect died would become impure, especially as excretions might leave the body upon prolonged contact. Moreover, this blood is not 'flowing blood' (dam masfuuh), which is what the Quran prohibited.
Supporting text
The second narration, attributed to Ahmad, indicates caution, stating apprehension about too much flea blood. Al-Nakha'i and Malik required washing if the blood became excessive and spread. However, apprehension is not an explicit declaration of impurity, but rather hesitation. Furthermore, what is attributed to fleas is likely their urine, which is not impure, and the urine of these small insects is generally not considered impure.