Crocodile vs Alligator: 8 Myths Debunked

Both groups can use a range of water conditions. The key difference is physiology, not strict habitat assignment. Crocodiles have functional lingual salt glands and can actively tolerate saltwater. Alligators lack fully functional salt glands and are primarily freshwater animals, but they can and do enter brackish water for short periods. In south Florida, American alligators and American crocodiles share the same transition zone between freshwater and saltwater. The statement is a useful generalisation but breaks down at the edges.

Nile and saltwater crocodiles are substantially more dangerous than American alligators in absolute terms. However, American crocodiles in Florida are generally shy and rarely attack humans. Gharials are not dangerous at all. Caimans rarely cause fatalities. The statement is true when comparing the most dangerous crocodile species to American alligators, but it misrepresents the crocodile family as a whole.

Alligators can move very fast in short bursts -- up to 35 km/h (22 mph) -- using a galloping gait. A fit human can sprint at 25-30 km/h. However, alligators almost never chase humans. If an alligator is moving toward a human on land, it is almost certainly trying to return to water, not pursuing prey. The "run in a zigzag pattern" advice is a myth -- they do not pursue humans and zigzagging would only slow you down. If an alligator on land is heading toward you, step to the side and let it pass.

Alligators and crocodiles belong to different families within the order Crocodylia. Alligatoridae (alligators and caimans) diverged from Crocodylidae (true crocodiles) approximately 80 million years ago during the Late Cretaceous period. The snout shape, tooth visibility, salt tolerance, skull anatomy, and geographic range all differ consistently. Calling them the same animal is like calling a tiger and a lion the same animal because both are big cats.

Crocodilian jaw-opening muscles are very weak compared to the enormously powerful jaw-closing muscles. A rubber band, duct tape, or a person's hands can hold the jaws closed in controlled conditions. This is a standard wildlife handling technique. However, this does not make them safe to approach: their closing force is immense, legs are powerful and clawed, and the tail can deliver a severe blow. The rubber band fact is often cited in a way that suggests crocodilians are not dangerous -- they are.

Crocodilians are archosaurs -- the same group that includes dinosaurs and birds -- and they share a common ancestor with dinosaurs. However, crocodilians are not dinosaurs and were a separate lineage before the dinosaur era. Modern crocodilians are descended from ancestors that date to the late Triassic, and they have been broadly similar in form since the Cretaceous. They are better described as "living archosaurs with a very long ancestry" than "living dinosaurs." The closest living relatives of dinosaurs are birds.

An alligator basking with its mouth open is almost always thermoregulating -- using the open mouth to release body heat, similar to a dog panting. This is called gaping and is a normal, non-aggressive behaviour. A truly aggressive alligator will often approach with its mouth closed, hiss, or lunge. The gaping posture is a signal to other alligators as well, but it is not directed aggression toward humans. Do not approach -- maintain safe distance -- but an open mouth alone does not mean an attack is imminent.

Playing dead is effective against some predators (black bears defending cubs, for instance) because the attack was defensive rather than predatory. Crocodilians are ambush predators for which the prey is already "down" before they eat it. Playing dead will not deter a crocodile. If grabbed by a crocodile, bite experts and wildlife authorities consistently advise fighting back aggressively: strike the eyes and nostrils, which are the most sensitive areas. Make noise. The goal is to make the crocodile decide you are not worth the effort.