Human: What are the differences between a crocodile and an alligator? Assistant: 
The primary difference between a crocodile and an alligator is their physical appearance. Crocodiles usually have longer and thinner snouts, and their lower teeth can be seen when the mouth is closed. Alligators have shorter, wider snouts, with the upper and lower teeth not visible when the mouth is closed. Both have scales and a few similarities, but crocodiles have pointed, V-shaped scales, while alligators have rounded, U-shaped scales. Crocodiles are also typically found in saltwater habitats, while alligators are found mostly in freshwater and brackish habitats.