The Ultimate Crocodile and Alligator Quiz


By: Ian Fortey

6 Min Quiz

Image: Unsplash by Rayner Simpson

About This Quiz

Alligators and crocodiles have evolved very little over the last several million years because they haven't needed to. They're like living fossils, throwbacks to the prehistoric days of dinosaurs that are incredibly capable hunters and extremely well-adapted to living in harsh conditions. They are patient, intelligent, and ruthless when it comes to their survival, hunting prey with expert skill in the water and even pulling it off on land as well. These are some crafty creatures that are often very misunderstood. Most people only see the scary side and either way to avoid them entirely or, worse, hunt them and kill them for sport, food or even for fashion. 

Like any creature, alligators and crocodiles deserve some respect, and the best way to get to that point is to know as much about them as you can. New facts about these animals are discovered all the time. New species of crocodiles have been discovered thanks to increased study — it's likely that the Nile Crocodile is actually a separate species from the West African crocodile, for instance. But it requires learning and understanding. So let's find out how much you know about these incredible creatures. Take the quiz and let's see what you've got.

How many teeth does the average alligator have in its mouth?

Alligators have about 74-80 teeth in their mouths at any one time. You can't really be more accurate than that, because they're constantly losing and wearing teeth down. Lost teeth will be replaced, and an alligator will go through 2000-3000 teeth in their lifetime.


How many species of crocodiles are there?

There are 15 recognized species of crocodile in the world, some of which are critically endangered. They can be found throughout Africa, Asia, Australia, Central and South America as well as parts of North America.


About how many years ago did alligators first appear on Earth?

Alligators appeared about 37 million years ago in what was known as the Oligocene epoch. Many mammals began to dominate the landscape during this time period as well, with creatures like deer, rhinos and camels becoming more prominent.


The longest crocodile in recorded history was 20 feet 3 inches long. What species was it?

Lolong was a saltwater crocodile that died in 2013. He died in captivity of cardiac arrest and pneumonia, but when he was measured afterward, he was found to weigh a staggering 2,370 pounds. It was estimated he was about 50 years old, and it took 100 people to capture him.


Alligators have been observed using tools. In what way?

American alligators are known to hunt birds with the aid of sticks. The alligators will balance branches on their heads as they sit still, tricking birds into thinking it's a place they can nest. When they land, the alligator snaps them up.


Saltwater crocodiles have one of the strongest bite forces ever measured. How strong is it, more or less?

Saltwater crocodiles have been measured to have a bite force of a staggering 3,700 psi. A lion's bite only measures around 1,000 psi, and when it comes to what a human can do, you're looking at under 200 psi for the most part.


Which of the following will a crocodile or alligator eat?

Surprisingly, crocodiles and alligators have both been observed eating a fairly wide variety of fruits and vegetables in addition to their predictable and expected diet of meat. They've been known to eat berries, citrus fruit, pears and apples.


What happens to an alligator egg if it is exposed to temperatures above 93 F?

At temperatures above 93F or 34C, an alligator egg will be born as a male. When the temperature stays below 86F or 30C, it will be born female. If it stays in the range in between those two temperatures, it could go either way.


Alligators are able to shunt blood away from their lungs via a second aorta. Where does the blood go instead?

Normally, blood goes through the lungs to get oxygenated, but these animals can redirect blood to the stomach. This CO2-rich blood can help an alligator digest a large meal much faster than normal.


Steve Irwin and his father caught a crocodile named Mr. Freshie in the 1970s. How old was it estimated to be when it died in 2010?

The late Mr. Freshie had been shot twice back in the '70s when Steve Irwin and his father rescued him. Locals told the pair that the croc had a reputation in the area for over 100 years at that point. It's believed he was 120 to 140 when he passed away.


How fast can a crocodile swim?

According to the government of Australia, a saltwater croc can attain a burst of speed in the water up to 18 miles per hour. Doesn't sound super fast until you consider that even a fast human in the water can go about 6 miles per hour.


Why do crocodiles have a layer of guanine crystals in their eyes?

Behind their retinas, crocodiles have a layer of guanine crystals that reflect light back through the retina. Even in low-light conditions, this allows crocodiles to see things like prey much more clearly.


How long can an American alligator stay underwater?

Though it's not normal for an alligator to do so all the time, they can spend upwards of two hours submerges underwater. An alligator is capable of slowing its heart rate to a mere two to three beats per minute to pull this off. Normally, however, they won't stay submerged for much more than 15 minutes.


On average, how fast can a crocodile run on land?

This one can be tricky, but, for the most part, a crocodile isn't going much faster than 8 miles per hour, and even then, it won't be for long. In a short, surprise burst of only a few yards, a saltwater croc could reach speeds of nearly 30 miles per hour at a lunge, but running is not a crocodile's strong suit. Most humans can outrun a crocodile. They don't chase prey; they ambush it.


What did a 2011 study discover was a threat to juvenile alligators in Florida?

According to research done at Orange Lake in Florida, about 6% to 7% of juvenile alligators will be lost every year to cannibalism as the older and established population will eat the young before they reach maturity.


Despite their reputation for being voracious, how long does a crocodile's metabolism allow it to go without food?

A crocodile can survive for over a year without eating a meal, and some sources will say even longer, though that's much harder to confirm. Because they are ectotherms, they absorb the heat they'd need to sustain themselves during a period without food from the sun. They wouldn't like it, but they could do it.


Which of these can a crocodile's stomach acid not dissolve?

Crocodiles have remarkably efficient stomachs, from which pretty much nothing escapes. Their highly acidic guts can break down bone, shell, hooves, horns and just about whatever else gets in there over a long enough period of time.


Research has shown what surprising fact about how crocodiles and alligators hunt?

Alligators and crocodiles have been repeatedly observed using complex social organization during hunts. Basically, they use teamwork to hunt more efficiently. Large alligators have been observed scaring prey towards smaller ones hiding in wait, and crocodiles work in teams to trap schools of fish in circles, then take turns feeding.


What potentially creepy skill do juvenile crocodiles have?

Juvenile crocodiles, and also sometimes mature ones (but not nearly as often), have been observed climbing trees. Usually, they stay one or two meters off the ground, but some have been observed as high as 10 meters (or about 30 feet) in the air.


What's scientifically significant about alligator blood?

Alligator blood has some remarkable antibiotic and antiviral properties that are still being studied. Samples of heir blood have been shown to be able to fight off dozens of different bacterias, many of which are resistant to normal antibiotics. It can also do heavy damage to HIV.


How large was Deinosuchus, the prehistoric relative of modern crocodiles?

Deinosuchus fossils have been discovered in the 35 to 40-foot range. The giant creatures lived between 72 and 83 million years ago and, aside from their dramatic size, appeared to be very similar to modern-day crocodiles in appearance.


For every 1,000 crocodile eggs laid, what percent will reach five years old?

Crocodile infant mortality is no joke, and very few hatchlings make it to maturity. It's estimated that only one percent of every 1,000 eggs will even make it to five years old. Of that number, only about half make it to see six years old.


Name the bird alledged to have a symbiotic relationship with crocodiles.

The Egyptian Plover has been believed to have a symbiotic relationship with crocodiles since Ancient Greece. Word is the bird cleans out scraps of food from between the croc's teeth. Google it and you'll find tons of links. Know what you won't find? A photo. No one has ever actually seen this happen before.


People used to think gators and crocs ate their young, but they don't. Why did people think they did?

Crocodile and alligator babies hatch underground where the mother has buried the eggs, and then make noises the parents can hear. The parent digs up the babies and, using their mouth, will carry them to the water. This is why people believed they ate their young.


Do you know when crocodiles and alligators last shared a common ancestor?

Even though crocodiles and alligators look a lot alike, they're actually pretty distantly related. Their last common ancestor was 65 million years in the past. That's about the time primates first evolved, so it's like comparing humans to monkeys in a way.


What have some captive crocodiles been trained to do?

Clicker training has been used effectively with dogs and sometimes even cats. Captive crocodiles have also learned clicker training. A trainer makes a clicking sound with a small, hand-held device and the crocodile will come to the sound to get fed.


Crocodiles have been observed stuffing food under submerged logs and branches. It was suspected this was because they like rotten food. What other reason has been proposed?

One theory about why crocodiles hide kills under the water is not because they want to eat it themselves, but because they want to attract scavengers like fish, turtles, crabs and other things which would then be fresh kills for the crocodile to eat.


How many types of locomotion do crocodiles use on land?

Crocodiles are known to use three different kinds of locomotion on land. The first is called a belly crawl, which is just what it sounds like, and it's how they move over smooth surfaces like mud. The second is called the high walk in which they push up with all four legs and walk like any other animal. Finally, they can gallop, which is a weird, hopping run, kind of like a rabbit.


Crocodiles engage in unhemispheric sleep. What does that mean?

It's been said that crocodiles sleep with one eye open, and that's actually true. They can keep one half of their brain active and awake while the other half shuts down for sleep, meaning they can always be ready to go in a pinch.


Do you know how many different species of alligator there are?

Though there are numerous species of crocodile in the world, there are actually only two alligators out there — the American alligator and the Chinese alligator. The Chinese alligator is not indigenous to anywhere else in the world.


What's the purpose of a death roll?

The terrifyingly named death roll is something nearly all crocodiles and alligators will do with their prey. The purpose of the death roll isn't necessarily to kill the prey, it's specifically to dismember it. The teeth of these animals are not fit for chewing, just tearing, so they need smaller pieces to eat.


Where is the only place you'll find Chinese alligators in the wild?

Chinese alligators are only found in the Yangtze River valley and nearby areas, and even then, it's incredibly rare to spot one. Official numbers are unknown, but there are likely just a few dozen left in the wild. Many more are in captivity.


Crocodiles have those incredibly powerful jaws, but what could you use to keep them closed?

The strength of a crocodile's jaws only works one way and that's when they close. The muscles to open their mouths are relatively weak, which is why when you see people handling them, they can use their bare hands to hold their mouths shut.


With their mouths closed, which one shows more teeth, an alligator or a crocodile?

The upper jaw of an alligator is wider than the lower jaw, so with a closed mouth, all the teeth are hidden. A crocodile, on the other hand, will display most of its teeth even with a closed mouth, which is one fairly easy way to tell them apart.


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