Small Nationally Scarce Beetle.
Black but with red elytra.
I kept the specimen but it is unpreserved, thus now dried out.
No interactions present.
Certainly looks possible for Platycis minutus, but I'm afraid I can't confirm it from the photo, e.g. Pyropterus nigroruber looks similar (although I think that has entirely black antennae).
Entomologist and biological recorder
Lat/Lng: 51.7063, -4.8617
OS grid ref: SN023047
Ancient woodland recently opened to the public.
Very damp but mild location.