It seems that butterflies have a rough time of their transition from caterpillars. These li'l caterpilliars weave weave weave and end up with a cocoon all aroung them, in which they're physically abe to transform into a butterfly. Now that's a lot of work all by itself, but the interesting part comes next: they have to get out of the cocoon. The butterfly in the cocoon has to REALLY struggle to get out of that thing. Now, let's say you're walking through a field, and you see this cocoon. It's pretty obvious there's a butterfly in there, struggling to get out. Humanitarian that you are, you bend down and very gently open the cocoon to free the butterfly. Good deed? Nope. It seems that nature in hir wisdom has decided that the butterfly NEEDS the struggle: the struggle itself triggers some sort of chemical process in the butterfly that allows it to live once it's out. If you free a struggling butterfly from its cocoon, you're signing it's death warrant.