Black beetle, 10mm (approx, relatively small head tucked under when threatened, deeply grooved elytra, prominant antennae.
No interactions present.
I would say Silpha atrata is the best bet for this, although there are 5 other members of this genus on the British list.
The latest edition of Beetle News is now available to download from the Amateur Entomologists' Society website:
It includes an illustrated key to beetles in family Silphidae, such as the one shown in this observation.
Entomologist and biological recorder
Lat/Lng: 52.6, 1.4
OS grid ref: TG3306