What an awesome thread! We just took our kids out of school to home educate. Im getting some pretty groovy ideas here and its spurring my own imagination. I had a look to see how much it would cost to purchase some butterfly eggs and its SO cheap!! Do I need a special cage to hatch them in?
There are companies that sell cages, but you could easily make one yourself - bonus activity! I've seen homemade cages made of plywood frames wrapped in a fine mesh. Make sure you have mesh on the top too so your caterpillar has something to hang from while making it's chrysalis (I prop up long hefty sticks for the same purpose). The most important thing is to have a plant your caterpillar will eat. Some caterpillars are very finicky (e.g., monarchs will only eat milkweed).