Oh, quite touching, just a had little 6 year old boy at my front door asking if I had seen his pet caterpillar because it had built itself a home a few weeks ago and when he looked today the home was open and the caterpillar had gone.
I explained to him as best I could in words, etc, that he'd understand, that his caterpillar buit his home so he could live in while he change from a caterpillar into a Butterfly or a Moth and that's what caterpillars do.
I hope he understood, well at least he looked like he did as he smiled and walked out of my front gate.