Found in the soil wile digging on the allotment.
No interactions present.
Someone else said it was a stag beetle.
I think they are only found in rotting wood.
You said this would found in soil - where these Cockchafers spend their early life.
Lat/Lng: 51.3837, 0.571
OS grid ref: TQ790680
Rural? Urban? Coastal? All of those ...