Like sharks, crocodilians never run out of teeth, for sharp new ones grow in as old dull ones are shed throughout the animals' lives. Numerous as they are, crocodilian teeth serve only for grasping, not chewing. These animals gulp their food in large chunks and rely on powerful stomach acids to break it down. Alligators and crocodiles both have thick, bumpy skin but alligators tend to be darker in color. Adult alligators are grayish black while adult crocodiles are light tan to brown in color.
Young alligators can be more colorful with yellow or white highlights on a black body.
Another difference between crocodiles and alligators is their choice of homes. Alligators are freshwater reptiles, favoring the rivers, lakes, swamps, and marshes of the coast. On the other hand, crocodiles prefer coastal, brackish, or salt water habitats. As far as we know, crocodilians are the only true archosaurs remaining alive today. Two crocodilians are native to the U.S., the American alligator and the American crocodile.