When I kept those camouflaged loopers for a day, I put them in one of my large plastic critter-keepers. Well one of the caterpillars decided the side of the cage would be a good place to pupate. So while the rest were released, I kept this one because it had silked up its decorations to the plastic. Over the next couple days I've watched it slowly transform, and today it finally looks more like a pupae than a caterpillar.
Only problem - now I can't use that whole big cage til this little guy is done!
Oh well, it'll be worth it to see the emerald moth that emerges.