Flies Calliphoridae have many kinds and different coloring. They are very sensitive to carrion and meat and immediately debug their eggs after discovering such protein stores. Their developing larvae need a lot of protein.
And the flies themselves are not averse to feasting on pollen and nectar from flowers. At their meal I suggest you take a look.
Сamera: Nikon D3400 | 55mm
Photo by @grildrig.
Very Nice Pic ! @awan55