The world's in a state of chassis Juno

A couple of nights ago we were settling down for the night when this thing on the left started dive bombing the bed. With no clue as to how an insect managed to survive this long into the winter or even that night, when the outside temperature was a couple of degrees below freezing we assumed that it came back with us from a week's holiday in Malta. Turns out it was a Peacock Butterfly and was probably asleep in a cupboard somewhere but thought it was spring when the heating came on. I'm nervous about what else might be lying dormant...