Worm poop, to be indelicate about it. Since my containers sit on concrete this is often the first indication that I have a worm gorging itself. Above this particular spoor was a cayenne pepper.It’s amazing how hard it is to spot these critters even when you know there is one there, somewhere. When you do, finally, spot them you are again amazed that you didn’t see it right away.This one is on a Thai pepper. I saw the poop under it a few days ago but I couldn’t spot the culprit. I thought that it had moved on. Then I spotted a branch shaking. He is so heavy that his own movement gave him away.