I am teaching a class with 3rd and 4th graders in it and they *enjoyed* this book. One or two students borrowed it and studied up on having a pet in a jar. We were studying insects at the time, so that is more'n likely what they were interested in. There are chapters on hydras, planarians, pond snails, water bugs, tadpoles, newts, toads, earthworms, ants, crickets, praying mantises, brine shrimp, butterflies and moths, hermit crabs and starfish, covering a wide range of pets that can be kept in a jar in your bedroom or classroom. This is a good book to have around if you or someone that you know wants to have a (small) pet of some kind. It is unlikely that they will recognize you or respond to you, but they will be interesting to observe! The book says, in part, "Most, if not all, will never learn to recognize you. Most will pay no attention to you at all. But these wild animal pets will let you see things about the way they live that are almost impossible to see in any other way."