Human: How do you tell a crocodile and an alligator apart? Assistant: 
A crocodile is a member of the family Crocodylidae. An alligator is a member of the family Alligatoridae. The two families are closely related, but they look different. The most obvious difference is that crocodiles have a snout that is longer than their body length, while alligators have a snout that is shorter than their body length. Crocodiles also tend to have more pointed teeth, while alligators have more rounded teeth.