Epic battle! Devil's Coach Horse Larva vs Earthworm
I was fascinated to find this happening when I was walking along the John Muir Walkway near Musselburgh today
The black creature is I think a devil's coach horse larva (please correct me if I'm wrong) and it was battling with the earthworm for several minutes. The larva seemed to give up eventually and wandered off but may have come back again later.