Milkweed and Monarchs

So, I blew it. Photgraphically, anyway. I was checking on my milkweed, in the bed out by the mailbox, on Sunday, when I noticed that many of the plants were being eaten. The main stem was still there, but each leaf was eaten down to the nubs. For maybe the first time in my gardening career, I was very happy about this. The culprits were monarch butterfly caterpillars! There were four or five of them, just hanging out. I called my daughter out to take a look--she thought they were way cool--but it NEVER occurred to me to get a camera! Doh. The next day they were all gone. I don't know if they pupated or got eaten. I'll keep an eye out, and bring a camera, when I check the mail this week...