Immature fly

Immature fly

Observation - Immature fly - UK and Ireland. Description: Found to be incapable of flight when clearing out a 43kg pile of Leisler's bat guano in a roof void. The fly looks recently hatched with uninflated wings. Some small (3 to 4mm) black flies were observed flying within the roof void - they did not look les

Found to be incapable of flight when clearing out a 43kg pile of Leisler's bat guano in a roof void.
The fly looks recently hatched with uninflated wings. Some small (3 to 4mm) black flies were observed flying within the roof void - they did not look lesser dung flies - Sepsis Fulgens.