When I was kid, I've kept silkworms as pets. Even now, I think they make great pets for little kids.
I still remember how I used to look for mulberry trees all over the neighborhood with other kids (I gave them baby silkworms). When I finally found one, I would get as much leaves as I can in a large plastic shopping bag, then store it in the fridge.
It was fun to watch them eat, and grow, molt the skin, eat, grow again. When they become big, white, and fat, I would make small boxes with hard paper, and stick toothpicks slightly into the bottom. It was exciting to watch them finally making cocoons, some between the toothpicks, some at the corner of the paper box. Once two silkworms even made one single huge cocoon, that was rare.
When they came out of cocoon, the males would go after the female and connect their rear together while vibrate their wings, although they couldn't fly at all. Then they'll lay eggs on the paper, and I would wait for the next generation.
Silkworms as pets 
