Lisa O
During the Cretaceous period, around 240 million years ago, our planet looked very different. Dinosaurs roamed freely, sharing their world with crocodiles. Crocodiles are remarkable survivors, thought to have lived through the asteroid crash that wiped out the dinosaurs. Now, let’s explore 15 interesting facts you didn’t know about crocodiles!
Crocodiles are Earth’s largest reptiles
The saltwater crocodile is the largest aquatic reptile on Earth, reaching lengths over 23 feet and weighing more than 2,200 pounds. Females are much smaller, typically growing to about 10 feet long and weighing around 330 pounds. These impressive creatures are most commonly found in coastal waters or rivers, where they can navigate between freshwater and brackish water.
They have a unique way of shedding tears
Have you ever heard of the phrase “Crocodile tears”? It refers to showing fake sorrow. This saying comes from the observation that crocs produce tears when they eat their prey. A study discovered that the tears in crocodiles might be caused by their hissing and huffing during feeding. When air is forcefully exhaled through their sinuses, it can mix with tears from their tear glands that empty into their eyes.
The oldest crocodile lived 140 years
Did you know? All crocodile species usually live for about 30 to 40 years, while larger ones can reach 60 to 70 years. However, there are exceptions to these averages. For instance, Mr. Freshie was a freshwater crocodile at Australia Zoo who lived an impressive 140 years in captivity—setting a record as the oldest known crocodile.
Their powerful jaws can’t chew food
A crocodile’s jaws can exert 5,000 pounds of pressure per square inch, making it the strongest bite of any animal. In comparison, a human’s jaw exerts only about 100 pounds of pressure per square inch. A crocs’ bite is ten times stronger than that of a great white shark. Crocodiles cannot move their jaws sideways, so they cannot chew food in the usual way.
They can hold their breath underwater for an hour
Crocodiles can stay underwater for an hour without needing to come up for air because they can slow their heart rate to just 2-3 beats per minute. Scientists discovered that crocs can control how much oxygen they use—which lets them stay submerged longer. The longest recorded time a crocodile held its breath is eight hours in cold water, where they use less energy and oxygen than in warmer water.
Crocodiles cool off by panting and not sweating
Crocodiles don’t have sweat glands on their bodies like humans do. Instead, they release extra heat through their mouths to stay cool. This is why you often see crocodiles with their mouths open in pictures—they’re trying to cool off. Crocs are cold-blooded reptiles, so when you see them with their mouths wide open, you will know that they’re not showing aggression.
They swallow stones to aid digestion
Crocodiles swallow small stones called ‘gastroliths’ to help digest their food better. These stones grind up the food in their stomachs, which is especially helpful when they eat prey whole or animals with hard shells and bones. Since crocodiles cannot chew, gastroliths play a very crucial role in their digestion process. These stones can remain in a crocodile’s stomach for many years, gradually aiding digestion over time.
Nest temperature determines baby crocodile gender
One of the most intriguing facts about crocodiles involves their breeding process. When a female crocodile lays eggs (sometimes up to 60 at once)—the temperature of the nest where the eggs are placed determines the gender of the babies. If the nest temperature is below 32 degrees Celsius, the baby crocodiles will be female. On the flip side, if the temperature exceeds 32 degrees Celsius, they will be male.
They hunt large prey like elephants and hippos
Crocodiles are predators that rely on ambushes and seize opportunities to hunt. They can capture large mammals such as smaller elephants, hippos, or big cats. Species like the freshwater crocodile mainly eat fish, whereas larger species, such as the saltwater crocodile and Nile crocodile, eat animals like zebra, deer, buffalo, and wild boar. When it comes to food—the diet of crocs varies significantly depending on whether they are in captivity or in the wild.
Crocodiles use grunts and hisses to communicate
Crocodiles use vocalizations to communicate. Young crocodiles of different species make squeaking and grunting sounds, while adults can grunt, growl, and hiss. For instance, Siamese crocodiles and caimans hiss loudly when they feel threatened, and hatchlings from most species produce grunts or quacks. Many crocodile species also react to other sounds—like engines, gunfire, or even people imitating crocodile noises.
Larger crocs can go over a year without eating
Larger crocodiles can go more than a year without eating. Their metabolism is highly efficient, using and storing nearly all the food they eat. In extreme situations, they can even slow down their metabolism and live off their own body tissues for a long time. Bigger crocs typically fast for longer periods compared to smaller ones—which might only go without food for a few weeks.
It’s illegal to hunt crocs for their skin in many places
In many regions worldwide—hunting crocs for their skin is against the law. The Endangered Species Act in the United States strictly prohibits importing products made from the skins of alligators, crocodiles, and related reptiles like caimans. Only items crafted from American alligator skin can be imported for personal, non-commercial purposes. However, the skins of most other crocodile species are banned from importation.
Crocodiles grow up to 4,000 teeth in their lifetime
Crocodiles have polyphyodont teeth, which means they can replace any that fall out or decay, much like sharks do. During their lifetime, crocs can grow up to 4,000 teeth. They typically have between 60 to 110 teeth. When a crocodile loses a tooth—a replacement is already waiting to take its place. Each of their teeth can be replaced up to 50 times throughout their life.
Their heart slows dramatically underwater
A crocodile’s heart is unique in the animal kingdom, with four chambers: two atria and two ventricles. This makes their heart one of the most sophisticated among animals. This specialized heart adaptation is beneficial for their aquatic lifestyle. When a crocodile is underwater—its heart rate can slow down to just one or two beats per minute. This helps conserve oxygen by reducing blood flow.
You can easily tell them apart from alligators
You can easily distinguish between a crocodile and an alligator by looking at how their teeth show when their mouths are closed. When a croc closes its mouth, you can see all its teeth because its upper and lower jaws are the same width. On the flip side, an alligator’s upper jaw has small depressions where the lower teeth fit in, so you can’t see the lower teeth when its mouth is shut.