When I checked the fennel plant today all the smaller caterpillars were gone. There was only one still feasting, and he was large and blended in with the green fronds. The smaller black ones are easy to spot and were probably a meal for a hungry bug or bird. Butterfly populations are dwindling and I’m annoyed with myself for leaving so many outdoors for the predators.
Indoors, to keep the caterpillars near the fennel and off the screens of the porch when they form a chrysalis, I placed the milk carton in a tight fitting ceramic pot and created an arrangement of sticks between the two. It works great! The sticks are stable, don’t blow in the wind, and even if knocked they seem to stay in place.
The largest caterpillar appears to be getting close to forming its chrysalis.
Do caterpillars think? Probably not, but this one certainly looks as if its contemplating what to do next.