No interactions present.
I'd agree it's a fly larva. Was it found on the moss surface? Don't have any real idea of what type of fly it is, but quite a lot of cecidyomiid flies ('gall midges', not all of which are gall formers) have orange larvae.
Entomologist and biological recorder
There were plenty of them some on moss surface some below
Lat/Lng: 51.954524631433, -0.65648138523102
OS grid ref: SP924293