The word alligator comes from the Spanish el lagarto, which means "the lizard.” Alligators and crocodiles can be correctly identified by looking at their mouths. When the jaws are closed, you can still see the fourth tooth on the lower jaw of the crocodile. However, when an alligator closes its mouth, that tooth is not visible. Female alligators construct and guard a nest for their eggs. The American alligator is a rare success story of an endangered animal not only saved from extinction but now thriving. State and federal protections, habitat preservation efforts and reduced demand for alligator products have improved the species' wild population to more than one million and growing today.