1. Crocodiles can be considered carnivores. This means that they eat meat only.  A recent study has shown that they can enjoy occasional fruit. According to a 2013 study, " There is little doubt that fruit is sometimes deliberately eaten, often in large amounts" , alongside their usual meat-heavy diets (mammals, birds, fish)

2. Crocodiles can have 4,000 teeth in a lifetime. Crocodiles can have 60 to 110 teeth. A small number of replacement teeth are always available in case a crocodile has to lose a tooth. Each of their 80 teeth can be replaced up to 50 times during their lives. 2

3. Crocodile jaws can exert 5,000 pounds of pressure per square in - the most powerful bite of any animal. In comparison, a human's jaw produces only 100 pounds of pressure per square in. A crocodile's bite is 10x stronger than that of a great White shark. 

4. Crocodiles are unable to open their jaws, so a rubber band or your naked hands can keep them closed. However, it's not recommended! It has allowed scientists to study them more closely!

5. A crocodile's ability to close its mouth makes it easy to distinguish between an alligator and a crocodile.  All teeth can be seen as long as the upper and bottom jaws are equal in width. An alligator has small depressions in its upper jaw to support the lower teeth.

6. The shape of the alligator's snout is another key distinction. Crocodiles have more pointed, V-shaped snouts. Alligators have broader, U-shaped noses. Crocodiles tend to be a bit more aggressive and are often stronger and larger than other animals.

7. The longest crocodile ever captured alive was 6.17m (20.2 feet) long and weighed 1,075kg (2,370 lb). This was taken by a National Geographic team from Agusan del Sur Province in the Philippines. 'Lolong’ was a saltwater-crocodile that was the largest ever kept in captivity. 

8. Crocodiles don't sweat. Crocodiles keep cool by opening their mouths, a technique known as "mouth gaping", which is very similar to panting. When they open their mouths, it is not an indication of aggression. To release heat, they often sleep with their mouths open.

9. Crocodiles can swim up to 35 km/h (22 mph b>). They use their powerful tails and feet to propel themselves through the water.

10. Crocodiles are known to be fast on the ground. For short distances, they can run up to 17 km per hour (11 miles per hour) Crocs are prone to fatigue on land, so they prefer to stay in the water. They come ashore to soak in the sun or lay eggs.

11. Crocs can hold their breathe underwater for up to an hour. Researchers at Cambridge have found that this ability is dependent on a small fragment of an animal's haemoglobin. This protein transports oxygen from the lungs to other parts of the body. 

12. To improve their digestion, crocodiles swallow small stones. These stones are used to grind the food into their stomachs. Swallowing stones, also known as "gastroliths", is particularly beneficial to crocodiles who eat their prey whole or for animals with bones and shells. The stomach can keep a gastrolith for many years.

13. Crocodile tears is an expression that refers to the emotion of crying crocodile tears (to show insincere emotion or false emotion) and comes from crocodiles' tears while eating their prey. Although this belief was once ancient, research has shown that crocodiles' eyes water when they eat. However, it is not due to remorse. This is because of the hisses and huffs they make during feeding.

14. Crocodiles are highly successful predators because of their keen senses. Crocodiles are nocturnal hunters, and they have excellent night vision. Crocodiles are very well-developed in their sense of smell, hearing and taste.

15. Crocodiles can sometimes cannibalize smaller ones. It has been reported that larger crocodiles have eaten smaller or younger crocs.

16. Crocodiles can prey on large mammals such as elephants, hippos and sharks. Some species, such as the freshwater Crocodile, prefer to eat fish while others, like the Nile crocodile and the saltwatercrocodile, like the Nile or the Nile, will eat buffalo, zebra, wild boar, deer, and zebra.

17. Crocodiles have one of the most acidic stomachs of any vertebrate. This allows them to digest bones,  hooves, horns, or shells of their prey.

18. Crocodiles use a "death roll" to defeat prey. They clamp on with their jaws and spin powerfully. The spin motion of the roll helps to disorient prey and drag them under the water. It also separates limbs from larger animals so they can be ingested easily.

19. Crocodiles communicate by vocalizing. Some species' young crocodiles squeak or grunt to communicate, while others can growl, hiss, or roar at one another. Many species also respond to other sounds, including gunshots or engine noises.

20. Crocodiles may sleep with their one eye open. Only birds, dolphins and other reptiles can do this. However, they sleep with their eyes closed.

21. Crocodiles larger than a crocodile can live for more than a year without ever eating. Crocs have a super efficient metabolism, using and storing almost all of the food they eat. They can even shut down and live without their tissue for long periods of time in extreme situations.