What is an alligator?

The alligator is a reptile belonging to the genus Alligator within the family Alligatoridae. Alligators are large animals with powerful tails used for defense and swimming. Their eyes, ears, and nostrils are positioned on top of their heads, allowing them to stay partially submerged while observing their surroundings. Alligators possess a broad, U-shaped snout, and when their mouths are closed, their lower teeth are not visible. They are carnivorous animals that live near permanent bodies of water like lakes, swamps, and rivers, often digging burrows for shelter. The American alligator ( Alligator mississippiensis ) can grow up to 4.5 meters (15 feet) in length, while the Chinese alligator ( A. sinensis ) only reaches about 2.1 meters (7 feet).

Where do alligators live?

American alligators are native to the Gulf Coast region of the United States. They live in freshwater environments such as rivers, lakes, swamps, marshes, and wetlands. Their geographic range extends from Mexico, northeastward to Oklahoma and Arkansas, and eastward through the Gulf Coast to North Carolina, South Carolina, Georgia, and Florida. Alligators spend most of their time hunting in the water but bask on land to increase their metabolism. They retreat to burrows in the soil when conditions are too warm or cold.

What do alligators eat?

Alligators, apex predators living near bodies of water, have a varied diet. American alligators eat invertebrates, amphibians, turtles, snakes, fishes, birds, and mammals such as nutria. Chinese alligators, smaller than their American cousins, consume fishes, waterfowl, insects, crustaceans, clams, and rodents. Both alligator species are carnivores that can adjust their diet depending on their size and the availability of prey. The American alligator has a wider snout, which delivers more crushing power to eat prey, especially turtles.

How can you tell the difference between an alligator and a crocodile?

Alligators and crocodiles, while similar, possess key differences. Alligators have a U-shaped, broad snout that delivers a powerful bite for crushing prey such as turtles. Crocodiles have a narrow, V-shaped snout . When an alligator closes its mouth, its lower teeth are hidden, whereas a crocodile's teeth are visible in an interlocking pattern. Color-wise, alligators are typically gray or black , while crocodiles are olive or tan. Alligators prefer freshwater habitats , while crocodiles are usually found in saltwater. Crocodiles are also generally more aggressive than alligators.

How do alligators care for their young?

Alligator mothers are dedicated caregivers. After laying eggs in a nest made of plant debris and vegetation, they guard them against predators. The sex of the young is determined by the nest's temperature. When the young are ready to hatch, the mother assists them out of their eggs and carries them to the water, protecting them for several weeks to months. The young alligators may join with young from other clutches in pods, which are protected by multiple females. They remain under their mother's care for up to two years, learning essential survival skills before becoming fully independent.

What role do alligators play in their ecosystem?

American alligators, as apex predators, play a crucial role in their ecosystem by preying on various species, including invertebrates, fish, birds, turtles, snakes, and mammals. They are opportunistic hunters, often capturing prey in or near the water. Alligators also create habitats; during the dry season, they take refuge in deeper "solution holes" in the limestone bedrock, providing refuge for other aquatic animals. Younger alligators serve as prey for birds, predatory mammals, and even larger alligators. The American alligator is listed as a species of least concern by the IUCN.

alligator

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Images

Side-by-side illustration comparing the heads of an American alligator (Alligator mississippiensis) and a saltwater crocodile (Crocodylus porosus) from a side view, highlighting differences in snout shape and structure.

Illustration of a Chinese alligator (Alligator sinensis), an endangered species, showing a dark, armored body and broad snout, with a length of about 200 centimeters or 79 inches.

Illustration of a Mississippi or American alligator (Alligator mississippiensis) with its mouth open, showing a broad snout, armored body, and thick tail, alongside a scale bar for size reference.

Top view illustration comparing the broad, U-shaped head of an American alligator (Alligator mississippiensis) with the narrower, V-shaped head of a saltwater crocodile (Crocodylus porosus).

At a Glance

alligator summary

Quick Facts

Related Topics:: American alligator; Chinese alligator; Are black caimans larger than alligators?; How long can alligators live?; Is an alligator a reptile?

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alligator

reptile

Also known as: Alligator

Written and fact-checked by

Britannica Editors

Last updated

Nov. 8, 2026 •History

News •

‘Never in a million years’: alligator strolls into North Carolina bagel shop • Nov. 4, 2026, 11:48 AM ET (The Guardian)

Alligator kills 71-year-old man fishing at pond in Florida • Oct. 17, 2026, 3:00 AM ET (CBS)

Top Questions

What is an alligator?
The alligator is a reptile belonging to the genus Alligator within the family Alligatoridae. Alligators are large animals with powerful tails used for defense and swimming. Their eyes, ears, and nostrils are positioned on top of their heads, allowing them to stay partially submerged while observing their surroundings.

Alligators possess a broad, U-shaped snout, and when their mouths are closed, their lower teeth are not visible. They are carnivorous animals that live near permanent bodies of water like lakes, swamps, and rivers, often digging burrows for shelter. The American alligator (Alligator mississippiensis) can grow up to 4.5 meters (15 feet) in length, while the Chinese alligator (A. sinensis) only reaches about 2.1 meters (7 feet).
5 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Where do alligators live?
American alligators are native to the Gulf Coast region of the United States. They live in freshwater environments such as rivers, lakes, swamps, marshes, and wetlands. Their geographic range extends from Mexico, northeastward to Oklahoma and Arkansas, and eastward through the Gulf Coast to North Carolina, South Carolina, Georgia, and Florida. Alligators spend most of their time hunting in the water but bask on land to increase their metabolism. They retreat to burrows in the soil when conditions are too warm or cold.
2 Britannica Sources
1. American alligator
2. 7 Crocodilian Species That Are Dangerous to Humans
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What do alligators eat?
Alligators, apex predators living near bodies of water, have a varied diet. American alligators eat invertebrates, amphibians, turtles, snakes, fishes, birds, and mammals such as nutria. Chinese alligators, smaller than their American cousins, consume fishes, waterfowl, insects, crustaceans, clams, and rodents.

Both alligator species are carnivores that can adjust their diet depending on their size and the availability of prey. The American alligator has a wider snout, which delivers more crushing power to eat prey, especially turtles.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How can you tell the difference between an alligator and a crocodile?
Alligators and crocodiles, while similar, possess key differences. Alligators have a U-shaped, broad snout that delivers a powerful bite for crushing prey such as turtles. Crocodiles have a narrow, V-shaped snout. When an alligator closes its mouth, its lower teeth are hidden, whereas a crocodile's teeth are visible in an interlocking pattern. Color-wise, alligators are typically gray or black, while crocodiles are olive or tan. Alligators prefer freshwater habitats, while crocodiles are usually found in saltwater. Crocodiles are also generally more aggressive than alligators.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do alligators care for their young?
Alligator mothers are dedicated caregivers. After laying eggs in a nest made of plant debris and vegetation, they guard them against predators. The sex of the young is determined by the nest's temperature. When the young are ready to hatch, the mother assists them out of their eggs and carries them to the water, protecting them for several weeks to months. The young alligators may join with young from other clutches in pods, which are protected by multiple females. They remain under their mother's care for up to two years, learning essential survival skills before becoming fully independent.
6 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What role do alligators play in their ecosystem?
American alligators, as apex predators, play a crucial role in their ecosystem by preying on various species, including invertebrates, fish, birds, turtles, snakes, and mammals. They are opportunistic hunters, often capturing prey in or near the water.

Alligators also create habitats; during the dry season, they take refuge in deeper "solution holes" in the limestone bedrock, providing refuge for other aquatic animals. Younger alligators serve as prey for birds, predatory mammals, and even larger alligators. The American alligator is listed as a species of least concern by the IUCN.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

alligator bellowingAn alligator bellowing.

alligator, (genus Alligator), either of two crocodilians related to the tropical American caimans (family Alligatoridae). Alligators, like other crocodilians, are large animals with powerful tails that are used both in defense and in swimming (see also crocodile). Their eyes, ears, and nostrils are placed on top of their long head and project slightly above the water when the reptiles float at the surface, as they often do. Alligators can be differentiated from true crocodiles by the form of their jaw and teeth. Alligators possess a broad U-shaped snout and have an “overbite”; that is, all the teeth of the lower jaw fit within (are lingual to) the teeth of the upper jaw. The large fourth tooth on each side of the alligator’s lower jaw fits into a socket in the upper jaw. Usually, no lower teeth are visible when the mouth is closed. In contrast, true crocodiles have a narrow V-shaped snout, and the large fourth tooth on each side of the lower jaw projects outside the snout when the mouth is closed. Alligators are carnivorous and live along the edges of permanent bodies of water, such as lakes, swamps, and rivers. They commonly dig burrows in which they rest and avoid weather extremes. The average life span of alligators is about 50 years in the wild. However, there have been reports of some specimens living beyond 70 years of age in captivity.

The American alligator (Alligator mississippiensis), the larger of the two species, is found in the southeastern United States. It is black with yellow banding when young and is generally brownish when adult. The maximum length is about 4.5 metres (15 feet), but it more typically ranges from about 3 to 3.4 metres (9.8 to 11.1 feet). The American alligator has been hunted for its hide, and its young have been sold in large numbers as pets. It disappeared from many areas where it was once abundant and was later given legal protection from hunters until it made an excellent comeback and limited hunting seasons were again established. The adult alligator feeds mainly on fishes, small mammals, and birds but may sometimes take prey as large as deer or cattle. Members of both sexes hiss, and the males also give loud roars that carry over considerable distances. During the breeding season, the female builds a mound nest of detritus and vegetation in which she buries between 35 and 39 hard-shelled eggs on average. She guards the eggs and may at this time be dangerous. Members of this species usually avoid humans.

The Chinese alligator (A. sinensis) is a much smaller, little-known reptile found in the Yangtze River region of China. It is similar to the larger form but attains a maximum length of about 2.1 metres (7 feet)—although usually growing to 1.5 metres—and is blackish with faint yellowish markings. Fewer than 200 Chinese alligators are thought to remain, and thus the species is considered critically endangered by the International Union for Conservation of Nature and Natural Resources (IUCN).