Metamorphosis

I'm a bit of a late starter this year, but when I saw swan plants for sale I decided I would grab a couple, especially as one had two teeny tiny caterpillars on it. They have been residing in the conservatory so that no passing monarchs are tempted to overload them with eggs. Due, I presume, to the excessive heat in the conservatory these tiny creatures have grown at an alarming rate. We came home yesterday evening to find they had stripped one plant and moved onto the other. 24 hours later and that one is half stripped and the slightly bigger caterpillar is ready to pupate. The other is still eating...