15 Amazing Facts About Alligators

Alligator with mouth open standing on grass

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Alligators members of the crocodilian family, which includes crocodiles, caimans, American alligators, and Chinese alligators. These cold-blooded reptiles can grow from six to 11 feet long and inhabit wetland areas. American alligators can be found throughout Louisiana and Florida, where they were once nearly extinct. Today, they are no longer endangered and, in fact, thriving in bayous, lakes, and even on some golf courses.

The only other species of extant alligator is the Chinese alligator, once widely distributed along the Yangtze River. Now, this alligator is critically endangered and limited just to the lower Yangtze. These mostly meat-eating reptiles fascinate many with their strength, speed, and ferocity—but there's even more to alligators than meets the eye.

From glow-in-the-dark eyes to amazingly loud roars, discover 15 of the wildest alligator facts.

Fast Facts

  • Common Name: Alligator
  • Scientific Name: Alligatoridae
  • Average Lifetime in the Wild: 50 years
  • Average Lifetime in Captivity: 60 to 80 years
  • IUCN Red List Status: American alligator, least concern; Chinese alligator, critically endangered
  • Current Population: American alligator, 750,000 to 1,060,000 mature individuals; Chinese alligator, 68 to 86 mature individuals

1. Alligators Are Ancient

alligator bones and teeth fossilized in rock
Ancient crocodile fossil.

markchentx / Getty Images

Alligators, along with other crocodilians, have undergone very little evolutionary change since the time of the dinosaurs. American alligators appeared about 84 million years ago, and their ancestors evolved more than 200 million years ago. The only older reptiles are turtles and tortoises.

Alligators are often called dinosaurs or dinosaur descendants. They aren't, actually, but they're more closely related to dinosaurs than to other modern reptiles.

2. They Can't Survive in Salt Water

Swimming alligator in grassy swamp area

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Unlike crocodiles, alligators don't have the glands to excrete salt from their bodies, so they can't swim in saltwater habitats like mangrove swamps. Now, they will hunt near saltwater, especially in the spring, experts say, when there's the greatest difference between high and low water.

But if you ever see a couple of eyes peaking up out of ocean water or any salty lake, it's certainly a croc, not an alligator.

3. They Can Weigh More Than 1,000 Pounds

Huge alligator on a log in a river

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The largest alligator ever measured was 15 feet, nine inches long and weighed in at 1,011.5 pounds. This gator was caught in Mill Creek, a tributary of a river in Alabama. Sadly, it was killed by a hunter in 2014, when it was believed to be between 24 and 28 years old. Gator hunting is still legal in the state of Alabama, but there are regulations.

P.S., if you thought 15 feet was long, consider the largest known crocodile: Cassius, a captive Australian croc, who is 17 feet long.  

4. Their Sex Is Determined by Temperature

Alligator eggs hatching

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One of the weirder facts about alligators is that the sex of them is determined not by DNA but, rather, by climate. If the temperature in the baby alligator nest is warm, male alligators are born; if the temperature is cool, the babies are females. Mother alligators lay their eggs on a mound of dirt. When the eggs are ready to hatch, the baby alligators use an "egg tooth" on top of their snouts to break the shell.

5. They Can Run Fast but Tire Quickly

Alligator running into the water from a marsh

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Alligators are built for speed, not endurance. They can run up to 35 mph—faster than most humans—but they are sprinters and can't keep up that pace for long. In the water, they can lunge at up to 30 mph. They can also swim very fast by using their powerful tails to propel them forward.

6. Their Eyes Glow in the Dark

Water full of alligator eyes glowing at dusk

George Shelley / Getty Images

Alligators' eyes are on the top of their heads, making it easy for them to lie almost entirely submerged in water and still see their prey. Alligators, like cats, also have a structure in the back of their eyes that reflects light to improve night vision. If you catch an alligator's eyes with a flashlight, they will glow red. You can also tell how big an alligator is by the distance between its eyes: the greater the distance, the longer the alligator.

7. They Prefer Meat but Aren't Opposed to Fruit

Alligator with head out of water and fish in mouth

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Alligators have long been considered carnivores but have more recently been discovered to deliberately eat fruit, vegetables, seeds, and legumes. For years before this was confirmed, the seeds found in their bodies during research were presumed to come from animals they'd eaten. Studies verifying this surprising part of their diets suggest that alligators even help the plants they eat distribute seeds (via the waste they leave... after digestion).

Still, though, meat makes up the bulk of their diets. Younger alligators eat bugs, amphibians, and small fish, while their parents feed on larger fish, snakes, turtles, birds, and mammals.

8. They Thrive in Slow-Moving Waters

Chinese alligator lying in still water

Mark Newman / Getty Images

All alligators live in freshwater; they usually prefer slow-moving rivers, creeks, marshes, swamps, and lakes. Often, they're found in deep water, especially during the breeding season.

American alligators live in slow waters in the southeastern part of the U.S., from North Carolina to Texas. The Chinese alligator, a close relative, lives almost exclusively in the lower Yangtze River in China.

9. Alligators Can Go Through 3,000 Teeth Over a Lifetime

Close-up of American alligator showing its teeth

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Alligators have about 75 teeth in their mouths at any one time, but as the teeth wear down or break off, they are replaced. As a result, many can have about 3,000 teeth over the course of their lives. According to some sources, alligators can bite with a force of nearly 3,000 pounds per inch, making their bite among the most powerful in the world. It's no wonder why they lose so many of their chompers.

10. They Care for Their Young, Unlike Most Reptiles

Mother alligator with babies on her back

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For about two years, female reptiles carry and look after their babies, making sure they are safe and well-fed. Though they are seen as ferocious predators, they are known to be very nurturing toward their offspring. Babies grow about a foot per year, so they are good-sized predators by the time they head off on their own.

11. Alligators Spend Months in Gator Holes

Alligators don't hibernate, but they do go through a dormancy period during colder weather. Before going dormant, they use their feet and snouts to dig out what's known as a "gator hole," a depression or tunnel in the mud. Gator holes can be up to 65 feet long, and they protect the alligators when it's too hot or cold for comfort.

During this brumation period, which can last up to five months, their heart rates and metabolism slow way down. They continue to breathe through their snouts, which they stick slightly out of the water. In the coldest areas, the water will freeze around them.

12. They Are the Loudest Reptiles in the World

Alligator in the mud, bellowing

NajaShots / Getty Images

Both males and females emit loud roars when they're mating—so loud they give alligators the title of "loudest reptiles in the world." For reference, their calls can reach 90 decibels—about as loud as a lawn mower—while human vocalizations typically max out around 70.

Males will roar not just to attract mates but also to scare off potential predators.

13. Alligators May Eat Their Young

Baby alligators with adult

Troy Harrison / Getty Images

Though they're known to care for their young relatively well, alligators will also sometimes eat them. Researchers noted that a large number of baby alligators seem to die off before maturity, and they investigated the cause. They discovered that baby alligator mortality is due, in part, to the fact that about 7% of them are eaten by their parents.

The reason for this is believed to be multiple paternity (baby alligators in a single litter can have different dads). Father alligators are a much bigger threat than mother alligators to their young, and it's likely because they don't know which belong to them.

14. Alligator Blood Is Antibiotic and Antiviral

A study found that wild alligator blood has both antibiotic and antiviral properties. In fact, it is active against HIV-1, West Nile Virus, and Herpes simplex virus. These properties also help protect the alligators themselves from infection after injury.

So far, their blood has only been studied in the lab and is so far not being used in human medicine.

15. Chinese Alligators are Critically Endangered

Side profile of a Chinese alligator's head

Mark Newman / Getty Images

While the American alligator is populous throughout its U.S. range, the Chinese alligator isn't as safe. It is critically endangered due to "habitat fragmentation and degradation, hunting, natural disasters (floods and drought), geographic separation, low productivity, and pollution," the IUCN says. Until the '90s, they were hunted profusely.

Currently, there are as many as 86 and as few as 68 mature adults in the species' native range.

Frequently Asked Questions
  • Can alligators sleep underwater?

    Alligators do sometimes sleep submerged in water because they can hold their breath for up to 20 minutes or, in cold water, hours. They normally sleep with at least their snouts out so they can continue to breath. This is how they "sleep" when they go dormant in the winter.

  • Are alligators blind?

    It's a common misconception that alligators have poor eyesight. They actually have very good vision and an excellent range of sight because of the position of their eyes on the tops of their heads.

  • How fast can alligators run?

    Alligators can run up to 35 mph for very brief stints. That's faster than the fastest person in the world, Usain Bolt, who is able to run at 27 mph.

  • Why do alligators keep their mouths open?

    Alligators will often be seen with their heads out of the water, mouths open, teeth showing. It's an ominous sight but not a symbol of aggression. They actually do this to cool down; they sweat through their mouths.

Save the Chinese Alligator

  • Consider donating to an organization that is helping Chinese alligator populations rebound, like the Wildlife Conservation Society, a U.S.-based nonprofit and U.S. Fish and Wildlife Service partner.
  • Do your best to reduce your personal carbon footprint—environmental pollution and natural disasters have historically wreaked havoc on the species.
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