An alligator has a wide, rounded snout. A crocodile has a narrow snout. An alligator closes its mouth. Its lower teeth are hidden. A crocodile closes its mouth. Large teeth stick out.

Alligators, crocodiles, caimans and gharials make up one group. The group is called crocodilians. The family Alligatoridae has eight species. Only two are usually called alligators. The Chinese alligator is the only other species of alligator. Alligators are not lizards. Scientists put lizards in a different order, Squamata.

The alligator is the largest reptile in the United States. This is true as of November 2026. Adult alligators weigh from 91 to 360 kilograms. The average is about 150 kilograms. Adult alligator lengths range from 257 to 437 centimeters. The average is about 350 centimeters. Female alligators rarely grow longer than 10 feet. Males can grow much larger. An alligator's weight depends on its habitat, its food and whether it is male or female.

A newly hatched alligator is about 6 to 8 inches long. Young alligators grow about a foot a year. Alligators are old enough to breed when they are about 6 feet long. As of November 2026, an alligator in the wild typically lives 20 to 30 years.

An alligator has upward-facing nostrils at the end of its snout. It can breathe with the rest of its body under water. An alligator usually takes a breath of air every 20 or 30 minutes.

Small sensory spots are around an alligator's face and jaws. They feel pressure changes in the water. The spots on its jaws are more sensitive than a person's fingertips.

An alligator eats fish, turtles, birds and small mammals. Alligators hunt mostly at night. An alligator uses its sharp teeth to seize and hold food. It swallows small food whole.

An alligator can go through 3,000 teeth in its life. The bite of a 12-foot, 665-pound American alligator was measured at 2,125 pounds of force.

Alligators live in fresh water. They live in slow rivers, swamps, marshes and lakes. They live across the southeastern United States. They range from the northern coast of North Carolina to central Texas. An alligator can stay in salty water only for a short time. A female alligator usually stays in a small area. A male can range over more than two square miles.

Market hunting and loss of habitat hurt alligators. The alligator was listed as an endangered species in 1967. In 1987 the U.S. Fish and Wildlife Service removed it from the endangered species list. As of November 2026, the International Union for Conservation of Nature rates the alligator as a species of least concern. As of November 2026, the main threat to alligators is the loss of wetland habitat.

An alligator nest is made of plants. It is usually 7 to 10 feet across. A mother alligator builds the nest. She lays about 20 to 50 eggs in it. The temperature of the nest decides whether a baby alligator is a male or a female. A mother alligator may carry her hatchlings to the water in her mouth.

Words to know

• crocodilians: alligators and kin
• nostrils: nose openings
• species: kind of animal
• hatchlings: newly hatched young