Beverly, your Giant ST cat there is in the process of molting. See how low his head capsule is sitting? That's because it's already detached from his body and the new one is forming underneath. I wonder if stretching helps them loosen the old skin in preparation for molting? Monarchs tend to roll side to side when they're molting and I always figured that's what they were doing. Interesting stuff.
I love it when the Spicebush think they're snakes. When they start swaying at me, I'm like, "Who thinks he's a wittle cobra?" Yes, I baby talk my caterpillars.
