Glass Frog
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40 free Glass Frog trivia questions with answers — trivia quiz, new questions added Oct 2026.
Glass frogs are small tree-dwelling frogs with skin so clear in places that you can look right inside a living animal. That one odd feature has made them favourites of wildlife photographers, and scientists have only recently worked out how it helps the frogs hide in plain sight. This quiz gathers the best fun facts about them: where they live, how the see-through trick works, what the parents do with their eggs, which animals hunt them, and how some species ended up with such strange names. Every answer comes with a short explanation, so you learn something even when you guess wrong. The set mixes easy questions with tougher ones, which makes it a good fit for curious kids, classrooms and anyone who enjoys unusual animals.
30 of 40 questions with answers and explanations. Play the quiz
Q 01Which part of a glass frog's body has see-through skin, giving the whole family its common name?
Belly
Belly skin so clear that the gut and other organs show through is what earned these small tree-dwellers their name. From above, most look like ordinary lime-coloured frogs.
Q 02Which organ can be seen completely exposed inside Ecuador's glass frog Hyalinobatrachium yaku?
Heart
Heart muscle can be watched at work in this species because the usual covering tissues are clear too. In some relatives a layer of pale tissue hides the organ from view.
Q 03Where do sleeping glass frogs hide most of their red blood cells to make themselves harder to see?
Liver
Liver tissue takes in most of the red cells at rest, which is why a dozing glass frog turns far more see-through. Once the animal is awake and active, the cells circulate again.
Q 04The glass frog nicknamed the Kermit frog was discovered in the Talamanca Mountains of which country?
Costa Rica
Costa Rica had hidden the species from earlier surveys, probably because its whistling call sounds more like an insect than a frog. Its bulging, puppet-like eyes then made it an internet star.
Q 05Which body parts of the emerald glass frog are coloured green by a pigment called biliverdin?
Bones
Bones tinted green can be seen through the thin skin of the living animal. Biliverdin is the same pigment that turns a healing bruise greenish.
Q 06How does a father Fleischmann's glass frog stop his eggs from drying out while he stands guard?
He urinates on them
He urinates on them, keeping the jelly-coated clutch moist on its leaf above the water. The guarding father also stays to protect the clutch from predators until the tadpoles hatch.
Q 07The Rio Azuela glass frog of Ecuador and Peru is described as about the size of what?
A fingernail
A fingernail is about right, since adults measure only around two centimetres from snout to rump. The species name, pellucidum, is Latin for transparent.
Q 08Which company released a playful interview with Kermit after a look-alike glass frog species went viral?
Disney
Disney, owner of the Muppets, had Kermit welcome his newly found look-alike in an official interview. The scientist who found the species said he had not noticed the resemblance himself.
Q 09Glass frogs differ from look-alike tree frogs because their eyes face in which direction?
Forward
Forward is the telltale difference, because the similar tree frogs of the family Hylidae have eyes that point out to the sides of the head.
Q 10Glass frog tadpoles often hatch and drop off their leaf during which kind of weather?
Heavy rain
Heavy rain helps wash the wriggling hatchlings off the leaf and into the stream below. The eggs need roughly ten to twenty days on the leaf to reach that point.
Q 11Scientist Brian Kubicki named the Kermit-like glass frog species dianae in honor of which relative?
His mother
His mother, Janet Diane Kubicki, supplied the name dianae. It took DNA testing to confirm that the little whistler was a species new to science.
Q 12Glass frogs live wild beside forest streams in which part of the world?
Central and South America
Central and South America are the family's home, and DNA studies suggest glass frogs first arose on the southern continent before spreading north several times.
Q 13The bare-hearted glass frog has another common name taken from which insect that the male's call resembles?
Cricket
Q 21The fringe-lipped bat tracks down male Fleischmann's glass frogs to eat by homing in on what?
Their mating calls
Their mating calls give them away, so the same peeps that attract a female can also bring a hungry bat. Males fall silent while they are busy guarding eggs.
Q 22Unlike leaf-laying relatives, the giant Pacific glass frog sticks its eggs to wet rocks beside what?
Waterfalls
Waterfalls keep the eggs soaked in spray on the wet rock, and males call from those same splashed rocks. It is the largest species in the family, about three times the length of a typical glass frog.
Q 23In tests of glass frog camouflage, which predators attacked see-through models less often than solid ones?
Birds
Cricket glass frog is its other name, because calling males sound so much like the insect. Rivals wrestle over the best calling leaf until one pins the other down.
Q 14The world's richest mix of glass frog species lives in which mountain range?
The Andes
The Andes hold the richest mix of species. Before a big 1970s study of Ecuador's frogs showed that, most known glass frogs had come from farther north, around Panama.
Q 15The powdered glass frog gets its name from a scattering of what across its back?
Small white spots
Small white spots speckle its back like a sprinkle of flour, and its scientific name, pulverata, means the powdered one.
Q 16What colour are the eyes of both Fleischmann's glass frog and the bare-hearted glass frog?
Golden
Golden eyes and raised nostrils mark out the bare-hearted species, whose underside is among the clearest of any glass frog.
Q 17Glass frogs reach their greatest variety in which type of damp, tree-covered tropical habitat?
Cloud forest
Cloud forest stays wrapped in mist for much of the time, and that constant damp suits small frogs that dry out easily. Some species also live in lowland jungle.
Q 18Glass frogs such as the red-spotted species grip wet leaves using what on the tips of their fingers?
Adhesive discs
Adhesive discs widen each fingertip into a sticky pad, letting the frog walk across wet leaves high above a stream. The widened tips are a family trademark.
Q 19Which part of a resting glass frog is the most see-through and so blurs its outline on a leaf?
Legs
Legs tucked against the sides let leaf colour fade gradually into frog colour, leaving no crisp outline for a predator to spot. The body itself changes brightness far less.
Q 20Which insects steal bare-hearted glass frog eggs one at a time while the father is away by day?
Wasps
Wasps can carry off a whole clutch egg by egg, because the night-active father is not on guard in daylight. After dark he returns to protect and moisten what is left.
Birds struck the see-through models far less often, giving the first experimental evidence that a glassy body really does work as camouflage.
Q 24Scientists testing glass frog camouflage made their model frogs from which kitchen ingredient?
Gelatine
Gelatine let the team cast both clear and solid-coloured fakes and set them out on leaves to see which were attacked. People were also tested on spotting frogs in computer images.
Q 25Emerald glass frog numbers fell sharply at Monteverde from the 1980s, and scientists suspect what kind of germ?
A fungus
A fungus called chytrid attacks the skin that amphibians partly breathe through. The emerald species came through the outbreak and is still rated as being of least concern.
Q 26Sleeping glass frogs pack their red cells tightly together without suffering which dangerous problem?
Blood clots
Blood clots would be the likely result in most animals, humans included, so doctors hope the frogs' trick can teach them how to prevent dangerous clotting.
Q 27Fleischmann's glass frog, or northern glass frog, reaches the northern limit of its range in which country?
Mexico
Mexico is as far north as any glass frog lives, and only in the country's tropical south. The species is named after Carl Fleischmann, who collected animals in the 1890s.
Q 28How do rival male emerald glass frogs position themselves when they grapple over a territory?
Hanging by their toes
Hanging by their toes from a leaf, the two males lock together chest to chest. The loser signals defeat by dropping to a lower leaf or flattening himself.
Q 29Researchers say glass frogs are not truly transparent but are better described by which word?
Translucent
Translucent is the better word, since light passes through their bodies but is tinted on the way. True transparency is rare on land and far more common among sea creatures.
Q 30What was written to celebrate Sabin's glassfrog of Peru becoming the 7,000th amphibian on AmphibiaWeb?
A song
A song marked the milestone, a rare honour for a frog known from just two streams in Manu National Park. Its name thanks Andrew Sabin, a supporter of reptile and amphibian research.