Yesterday evening (Wed) at 2040hrs I watched this brown slug feeding on the black ruptured one. Just wearing reading glasses I could see it’s mouthparts moving up and down; pity I couldn’t recapture it using the camera.
At 0840hrs today Thursday, there were two black slugs clearing up the last mouthful. Waste not, Want not.

PS Scroll halfway down the page for the most recent Animal Record entries.