Why do children love dolphins? Dolphins are powerful, fast and extremely intelligent. They're playful, they look like they're always smiling, and they live unfettered by human rules. What's not to like? Dolphins can be a great preschool introduction for topics such as undersea habitats, conservation, echolocation -- even the letter D. Try one of these crafts as part of a dolphin-themed lesson plan, or simply as a way to entertain your dolphin-obsessed preschooler.