Butterfly in Snow

On our first day of significant snow, let's take a short trip back to summer. Yes, it's a butterfly. Where do butterflies go when they die? Two summers ago, J- and one of our cats saw this butterfly doing loopty loops near his car in the driveway during a rain storm. It landed on the window and then it flew away. The next thing J- knew, it had landed on his cheek and then flew into an open window on his car. He searched inside but couldn't find it. He got on his iPhone and searched out what attracts butterflies and what they eat. He even placed sone sugary water in his car. He then lost track of it. He couldn't find it al all. A few days later, he located it near his rear window. RIP. That was two summers ago. Now, look at this. There she lies still at the back window, amid a few early big flakes. 
Where do butterflies go when they die?