I'm keen to identify a cluster of what looks looks like bugs that have appeared on a wall in the hall of my house.
From a distance it appears as a smudge on the wall about 6 feet from the floor, but on closer looking I see a disc about 30 mm in diameter containg about 100 black or dark brown wormlike creatures each about 2mm long. At least I think they're creatures and not eggs. I thought I noticed some movement, and when I got very close and inadvertantly breathed over them, some fell off to the floor.
There doesn't seem to be any kind of food source nearby nor within the disc. Most of the bugs are attached flat to the wall, but some appear to detached slightly as if held on by microscopic threads.
Here's a photo - the background is actually white paint...
I think they're young caterpillars that have recently emerged from eggs. They may have eaten the eggs - valuable protein, not be wasted. You probably didn't notice the eggs because they would have been white, or pale at least. So, if you want them to survive, now you need to find a suitable host plant.