Nancy's family gave us the idea of getting some caterpillars and watching them turn into butterflies. She lent us their butterfly "habitat" and we ordered some larvae (those are caterpillars) from a science store online. (They aren't expensive--about $12 for a kit of 5, although we got 6 for some reason.) They came in a little container with their food in it. At first they were quite small.
They just crawled around in their little cup for a week or so, and ate their food, and grew. Sebby loved to watch them (he loves The Very Hungry Caterpillar book) and talk about how they were getting "bigger and bigger."
Then one morning we saw them all hanging from the top of the cup. As the day went on, they turned from spiky little caterpillars into smooth-looking, shell-like . . . chrysali? chrysalae? . . . or, as we preferred to call them, cocoons. :) You're supposed to wait 24 hours for them to harden, and then tape them (attached to the paper top of the cup) to the butterfly habitat.
After about another week, one day Abraham noticed that some butterflies had emerged! They left their papery cocoons behind, and almost immediately started flapping their wings to make them stronger. ("Came out cocoons!" said Sebby excitedly.)
This part was very interesting to watch! 3 butterflies came out one day, and 3 the next. Unfortunately we could never catch them in the act of emerging, but we did watch them as their wings got stronger and they began to fly around instead of just hang there. (I like this picture of Sebby peering up at the butterflies.)
The butterflies were so beautiful! Abraham and Sebastian loved watching them fly around in their habitat. We fed them with sugar water. We just soaked paper towels with the water and put the towels in the habitat, and the butterflies landed on them and sipped up the nectar.
We waited for a nice sunny day, and then let them fly away. It was fun to watch them go up into the sky. Sebby said, "Butterflies! Flew away!" And Abe said, "If I were a butterfly, I'd want to be out in the big world! And if anybody ever sees a butterfly sipping from a nice flower, maybe it will be one of ours!"