The other day I spotted a green shield bug (Palomena prasina) on a wood dock leaf. This is a common species that emerges from hibernation at this time of year.
After it had wandered off the leaf I noticed a couple of small, shiny black sub globulare objets. At first I thought they were small beetles or molluscs but, on closer inspection, I concluded they were droppings from the shield bug - a long awaited response to the call of nature after hibernation maybe.