I'll keep trying - I might get one right one day.
No interactions present.
... are they part of the Muscidae? better to say Muscid fly?
Muscidae (family) has a large number of genera, of which Musca is one. 'Muscid fly' is just another way of saying 'Muscidae'.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
Lat/Lng: 51.3755, 1.3252
OS grid ref: TR315692