Long bodied black larva, tapering body, 10 segments, quick mover
No interactions present.
I often find larvae like this in pitfall traps and I've always assumed they are Carabus spp, see http://www.commanster.eu/commanster/Insects/Beetles/SpBeetles/Carabus.mo... (we most often see Carabus violaceus, C. problematicus and C. nemoralis)
Lat/Lng: 53.1, -3.1
OS grid ref: SJ2964