OKAY so this is short and probably quite boring but this is how fast they eat. In this case it’s eating parsley. There is no sound unless you hear the background sounds of my camera or fridge !!!! The caterpillar is now in it’s position to begin pupating [form it’s chrysalis] it should stay in it’s chrysalis until next spring when the adult butterfly emerges. But it isn’t uncommon for it to emerge in around 10 days so it will be a wait and see here : )