Shedding & eating

As the caterpillar sheds it goes through all sorts of positions to do so. Twisting and curling. Is a time consuming hard thing for it to go through. For a little being it goes through a lot of hard work and stages to become a monarch butterfly.
As it eats,when it is very small and has just emerged from it's egg. You will see a half circle shape in the milkweed leaf alerting you to it's becoming a caterpillar. They are very tiny at first. But grow very quickly.