A crocodiles is able to replace each of its 80 teeth up to 50 times during the course of its lifetime.

Crocodiles are very fast swimmers, which helps them catch their prey. They can swim up to 20 mph (32 kph) and can hold their breath underwater for around one hour.

Crocodiles are the closest living relatives of birds, sharing a common ancestor called the "archosaur" that lived around 240 million years ago and also gave rise to the dinosaurs.

The old myth about "crocodile tears" is actually true. Crocodiles really do cry while they eat, but not from any sense of reptilian remorse. They swallow too much air while feeding, which triggers their lachrymal glands (glands that produce tears) and forces the tears to flow.

Typically, crocodiles will drag their prey underwater until it drowns. Once the prey is dead, they will bring it up to the surface of the water to consume.

After baby crocodiles hatch, the mother carries her hatchlings to the water in her mouth. Instinct prevents her from closing her jaws, so the young are safe from her large, sharp teeth. A mother crocodile can carry as many as 15 babies in her mouth at once.

Crocodiles have a very high infant mortality rate. In their first year of life, 99% of hatchlings are eaten by other predators like adult crocodiles, carnivorous mammals, birds, and even fish.

Crocodiles have a very slow metabolism, which allows them to survive long periods without food. In fact, larger crocodiles can go for over a year without eating a meal.

Swallowing stones known as "gastroliths" is beneficial for crocodiles who eat their prey whole. These stones help grind the food inside their stomachs.

The largest living reptile and most aggressive of all crocodiles, the saltwater crocodile (Crocodylus porosus) is native to saltwater habitats and brackish wetlands in Southeast Asia and Northern Australia. An opportunistic hypercarnivorous apex predator, it ambushes its prey and swallows it whole. Males can grow to a length of up to 6.3 m (21 ft) and weigh up to 1,300 kg (2,900 lb).