Last weekend, I went to a state conservation education program on Monarch butterflies. We learned about butterfly biology and migration, and learned about the current generation of "super generation" monarchs, the butterflies that will make the massive migration south to Mexico (from the upper midwest).
We also learned about infections with something called "OE" (read more at Monarch Watch).
I had thought that Monarchs eat exclusively milkweed, but that's wrong. They only lay eggs and have larva succeed on milkweed, but once they're adults, they eat all sorts of flower nectar.
Finally, we got to participate in a monarch tagging project. Here I am, squeezing a tag gently into place on a monarch wing before turning it loose again.
The tags are marked pieces of plastic (I think) with specific numbers and adhesive on one side. You record the number, then press them into place. (Check Monarch Watch for more info, linked above.)
Anyway, it was a superb program, very interesting and a lot of fun. The other people involved were mostly seniors, like me, with a few teens.