Many packs hold a child up to 45 pounds. Plenty of water. Some packs have loops on the outside for water bottles, a nice feature that eliminates fumbling inside the pack every time you or your child wants a drink. Consider whole-wheat breadsticks or string cheese, apples or pears, raisins or other dried fruits, graham crackers, bran muffins, fig bars, ginger snaps, and, of course, trail mix. Your child probably doesn' t need hiking boots for a short nature walk.
Long socks keep poison ivy or poison oak from rubbing up against exposed ankles.
An extra pair of shoes and clothes. Bring the Experience Home Introduce some pond ecology. The owl tags the frog. And the hawk tags the fish. Then switch roles.