While your cat is batting around a ball of aluminum foil, chances are there's a gator out there doing the exact same thing. Crocodilians all engage in the three types of play distinguished by ethologists (locomotor play, object play and social play). In my last article, I mentioned that some reptiles engage in one type, such as turtles, but others, like monitors, engage in all three. It is safe to say that intelligence and play go hand in hand.
Crocs have been observed doing lots of strange things that if observed in a mammal would undeniably be called playful behavior. They'll play with their food, wooden balls, flowers, and other things floating in the water. They also surf the waves, seemingly for fun. Young caimans will engage in social play by "courting" each other or riding on each others backs. Further reading about reptilian play behaviors can be found here.
3. "Invisible whiskers"
Whiskers are sensory hairs that are used to detect minute movements in an animal's immediate vicinity. People tend to think that if an animal has scales, it means their sense of touch is dull. Recent research has uncovered that crocodilians' faces are very sensitive, much more sensitive and delicately tuned than humans. They can detect a single drop of water falling into a pond from just a few feet away through something called the trigeminal nerve. This sensitivity is akin to the sensitivity of other animals possessing special sensory hairs or whiskers on their faces. The trigeminal nerve in these animals is large on its own, and proportionately much larger comparatively to humans. The next step for evolutionary biologists is to determine how, why and when these structures evolved in their history.