I think, this website is tremendous, not only for children but for adults as well:
Infrared light shows us the heat radiated by the world around us. By viewing animals with a thermal infrared camera, we can actually "see" the differences between warm and cold-blooded animals. Infrared also allows us to study how well feathers, fur and blubber insulate animals. As you tour this "Infrared Zoo", see what new information you can gather about the animals here that you would not get from a visible light picture.
The Infrared Zoo Gallery