50 free Crocodile trivia questions with answers — nature quiz, new questions added Aug 2026.
Crocodiles have barely changed in 200 million years, and this quiz explains why they never needed to. It covers how to tell a true crocodile from an alligator, the saltwater crocodile's record-breaking bite, why a crocodile cannot stick out its tongue, how the temperature of the nest decides whether hatchlings are male or female, and how a mother carries her babies to the water in her mouth. There are questions on the famous individuals too: Lolong, the 6.17-metre giant measured in the Philippines; Gustave, the Burundian man-eater; Mr Freshie, rescued by the Irwins and thought to have lived past 120; and Yai, the hybrid that grew to 1,200 kg on a Thai farm. The set finishes with crocodiles in human culture, from the Egyptian god Sobek and the fable of crocodile tears to the Lacoste logo and Steve Irwin. Easy questions ask which crocodile is biggest and where they live; hard ones want bite-force figures, incubation temperatures and Greek etymology. Every answer was checked against Wikipedia's articles on the crocodile family and the species and individuals involved, and each question carries the sentence that supports it. Try our Alligators quiz next to see how well you know the other side of the family.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which is the largest living species of crocodile, and the largest living reptile?
The saltwater
Males can pass 6 metres and 1,000 kg; it ranges from India's east coast through Southeast Asia to northern Australia.
Q 02Compared with an alligator's, a crocodile's snout is generally what shape?
V-shaped and narrower
The other giveaway is the teeth: a crocodile's lower teeth stay visible when the mouth is closed, whereas an alligator's tuck into pits in the upper jaw.
Q 03Which lower crocodile tooth fits a notch in the upper jaw and shows when the mouth is shut?
The fourth
For hard-to-tell specimens, that protruding tooth is the most reliable way to decide whether you are looking at a crocodile or an alligator.
Q 04The bony plates that armour a crocodile's back are called what?
Osteoderms
They are richly supplied with blood, help the animal soak up heat and even bank calcium for eggshells.
Q 05The Greek word that gave us 'crocodile' translates roughly as what?
Stones worm
It shows up in an Aesop's fable from the sixth century BC, and Pliny the Elder Latinised it as crocodilus.
Q 06Who named Crocodylidae as a family in 1807?
Georges Cuvier
The family sits within the superfamily Crocodyloidea, which also holds several extinct crocodile relatives.
Q 07How many living crocodile species were recognised as of 2025?
18
That count may still grow: genetic work suggests the dwarf crocodile genus Osteolaemus hides a third, unnamed species.
Q 08Molecular studies show crocodiles are more closely related to which group than to alligators?
Gharials
That overturned earlier family trees built on skull shape alone.
Q 09Why can't a crocodile stick out its tongue?
It is held down by a membrane
The tongue does carry salt glands, though, which is one thing that separates crocodiles from alligators.
Q 10Newly hatched crocodiles are roughly how long?
20 cm
From that start, the biggest species' males can grow past 6 metres over a lifetime that may exceed 70 years.
Q 11The smallest living crocodile species, the dwarf crocodile, grows to roughly what adult length?
1.7 to 1.9 m
Adults weigh only 18 to 32 kg; some in the caves of Abanda, Gabon, have turned orange from alkaline bat guano eroding their skin.
Q 12Yai, the largest crocodile ever held in captivity, was a hybrid of the saltie and which rarer species?
Siamese
He lived at the Samutprakarn Crocodile Farm in Thailand from 1972 to 2025 and reached 6 metres and 1,200 kg.
Q 13Lolong, the longest crocodile ever captured alive at 6.17 m, was caught in which country in 2011?
Philippines
It took around 100 people three weeks to land him in Agusan del Sur; he died of pneumonia and cardiac arrest in 2013.
Q 21Stones swallowed by crocodiles, possibly as ballast or to crush food, are called what?
Gastroliths
Birds do something similar with grit; the stones may also help the animal trim its buoyancy.
Q 22Herodotus claimed a bird entered crocodiles' mouths to pick out leeches. Which bird?
Egyptian plover
No one has ever documented it happening in any crocodile species, so it is most likely a fable.
Q 23Roughly what bite force did the 4.59-metre saltie that set the laboratory record for any animal produce?
3,690 lbf
It beat a 3.9-metre American alligator's 2,125 lbf; a field measurement on a big Nile specimen exceeded 5,000 lbf.
Q 14Roughly how many times can a crocodile replace each of its teeth over its lifetime?
Up to 50
A small replacement tooth waits beside each of the 80 grown ones, with a stem cell in standby behind it.
Q 15Unlike other reptiles, a crocodile's heart has how many chambers?
Four
That, plus a cerebral cortex, puts crocodilians among the most biologically complex reptiles; they are closer to birds than to lizards.
Q 16Crocodilians belong to which group, along with birds and other dinosaurs?
Archosauria
The name means 'ruling reptiles'; it makes a crocodile a closer cousin of a pigeon than of a lizard.
Q 17Crocodiles have no sweat glands, so how do they shed heat?
Through their open mouths
They often sleep with their jaws agape and can pant like a dog.
Q 18What shape are a crocodile's pupils?
Vertical slits
Like a cat's, they shut out bright light by day; a reflective tapetum lucidum behind the retina boosts night vision.
Q 19The black speckles on a crocodile's jaws are sensory pits that can detect what?
A single drop hitting the water
They are the crocodilian version of a fish's lateral line; true crocodiles also carry them on nearly every scale of the body, alligators only on the jaws.
Q 20Crocodiles have the most acidic stomach of any what?
Vertebrate
It dissolves bones, hooves and horns; many crocodiles also swallow stones as ballast or grit.
Q 24Which crocodile weakness lets handlers subdue one with tape or a large rubber band?
Very weak jaw-opening muscles
Nearly all the jaw muscle is arranged for clamping shut, so a band cut from a car inner tube will hold the mouth closed.
Q 25The extinct giant Deinosuchus is estimated to have bitten with roughly what force?
23,100 lbf
That is nearly twice the latest estimate for Tyrannosaurus, at 12,814 lbf.
Q 26The land speed record for a crocodile, set by a galloping Australian freshwater croc, is roughly what?
17 km/h
Several species can gallop; most rely on the 'belly run', a snake-like slither reaching 10 to 11 km/h.
Q 27Three rogue 'salties' moved 400 km by helicopter in northern Australia did what within three weeks?
Returned to their original homes
Tracking devices showed the homing instinct at work; relocation is not a reliable fix for problem crocodiles.
Q 28How old was Mr Freshie, the freshwater crocodile the Irwins rescued around 1970, estimated to be?
120 to 140
He had been shot twice by hunters and lost an eye; he died at Australia Zoo in 2010.
Q 29Before bellowing, male crocodiles emit a 10 Hz infrasonic signal that makes the water do what?
Appear to 'dance'
The vibrations travel long distances through air and water to advertise the male's presence.
Q 30Depending on the species, a crocodile clutch contains how many eggs?
7 to 95
The eggs are hard-shelled but translucent when laid, usually at night, into a hole in sand or a mound of vegetation.