Not graded
Bulugh al-Maram 14b
وَأَبُو دَاوُدَ, وَزَادَ: { وَإِنَّهُ يَتَّقِي بِجَنَاحِهِ اَلَّذِي فِيهِ اَلدَّاءُ } 1 .
1 - سنن أبي داود (3844) وإسنادها حسن.
and Abu Da’ud who added:
“It (the fly) protects itself with the diseased wing (by dipping it first in a drink).
Cited in Bulugh al-Maram (No. 14b).