Frog Hydration: How Do They Drink Water?



Written by Katie Piercy

Frogs don’t drink water by swallowing it with their mouths. Instead, they absorb it through special patches in their bellies, known as drinking patches.

How do they drink?

Frogs are amphibians, and like all amphibians have very thin skin. This thin skin comes with advantages and disadvantages. One of the disadvantages is that they lose water very quickly, meaning they are largely associated with damp habitats such as wet meadows, ponds and rivers.

By spending most of their time in cool, dark places, they reduce the risk of dehydration, which could quickly result in their deaths. They also have specialized glands on their skin that exude mucus. This layer of mucus helps keep them moist.

With such a serious disadvantage to being thin skinned, why do frogs put up with it? The upside of thin skin is something we may never consider possible based on our own biology. Frogs can both breath and drink through their skin.

Frog SpeciesHydration StrategyAdditional Information
Desert Rain FrogExtracts moisture from sand and fogSurvives in arid regions by utilizing available moisture in the environment
Fire-bellied ToadAbsorbs water through its skinSkin acts as a permeable barrier, allowing water absorption from the environment
Waterfall FrogImmerses itself in water to stay hydratedLives in water-rich environments and stays hydrated by remaining submerged
Poison Dart FrogGains hydration from water-rich food sourcesAcquires moisture by consuming prey items with high water content
Table: Hydration Strategies in Different Frog Species

In both cases the mechanics are fairly simple. Blood vessels, close to the surface of the skin, allow an exchange of gases and liquids to occur through osmosis. Essentially, gasses and liquids pass through the skin because the they are higher on one side than the other, creating enough pressure to help them pass through.

Research has discovered that these blood vessels circulate more quickly if the frog is dehydrated, bringing water into the body more quickly. While frogs can technically absorb water through all their skin, the majority is absorbed through drinking patches, located on their bellies.

To aid the absorption of water, frogs will lay in puddles with their limbs outstretched, allowing maximum surface availability between the water and their drinking patches. While many species spend a great deal of time near waterbodies, such as ponds, lakes and rivers, many species of frogs will need to take advantage of whatever temporary pools of water are available, such as puddles of rainwater or pools accumulated within rotten wood.

Frog SpeciesWater Source PreferencesAdditional Information
Tree FrogDew, rainwater, water droplets on leavesWell-adapted to arboreal environments and rely on moisture for hydration
BullfrogPonds, lakes, slow-moving streamsHighly aquatic species that spend a significant amount of time in water
Dart FrogMoisture on forest floor, water-filled plantsObtains water through direct contact with moist surfaces and plant sources
African Clawed FrogAquatic environments, including rivers and swampsPossess specialized skin adaptations for water absorption and respiration
Table: Frog Species and Their Water Source Preferences

Also read: Here’s “How Frogs Find Ponds”

How do frogs swallow?

It may seem bizarre that frogs would choose to drink through their skin rather than their mouths. After all, they are perfectly happy to eat using their mouths, so why not drink too? Perhaps it is something to do with the mechanics of how a frog swallows.

Frogs do not have teeth, meaning that once the food is in the frog’s mouth, they don’t crunch down on it to break it up into smaller pieces. Instead, they simply swallow the food whole, and often alive, letting their stomach acids take care of it. In order to forced the food down their throat, they need to swallow. But to do this, frogs use a rather bizarre and unexpected body part; their eyes.

Frogs close their eyes and push them down into their mouths, so as for force food down their throats. While this works perfectly well with larger items such as flies or crickets, it might be more difficult on a liquid. Either this or absorbing water through their skin was simply so natural for them that they never bothered to investigate other options.

Also read: Wondering if “Frogs Eat Mice?”: Let’s Find Out

Do they need to drink?

Frogs do need to drink freshwater to survive. Amphibians can be very vulnerable to drying out, and can quickly dehydrate in dry conditions. Their thin skin also makes them very sensitive to pollution and can be the first species to react as habitat becomes degraded. If water sources become contaminated, their thin skin means they can easily take in toxins when absorbing water.

Frog SpeciesWater Conservation TechniquesAdditional Information
Spadefoot ToadBurrows underground to escape arid conditionsEmerges from its burrow after rain to absorb water and rehydrate
African Reed FrogCreates a waterproof cocoon to minimize water lossConstructs a protective layer around its body to retain moisture
White’s Tree FrogStores water in its bladder for extended periodsCan store water in its urinary bladder and reabsorb it when needed
Tomato FrogDevelops a waxy layer on its skin to retain moistureProduces a protective coating on the skin that reduces water loss
Table: Water Conservation Techniques in Frogs

Do pet frogs need water?

While frogs in the wild need to make do with whatever water they can find, pet frogs need to be provided with the right conditions to thrive. Although all frogs need water, frogs can survive in many different habitats. Some habitats can be particularly damp, such as rainforests, while others are drier.

It’s important therefore to provide pet frogs with the right conditions for the species, with some needing regular misting with water, while others only need water provided to drink from. In most cases frog owners will create shallow areas of water, big enough for the frogs to sit in, in order to drink. While most frogs can survive underwater for long periods of time, it’s essential that they can easily get out of the water again.

Happy as a frog in a puddle

Like all living things frogs need a certain amount of water to survive. How much water they need varies between species, with some frogs even adapting to life in deserts. But however much they may need, they all have an extra special way of taking a sip. Through their bellies.


Katie Piercy

Katie Piercy, a conservation industry veteran with a diverse career, has worked in various environments and with different animals for over a decade. In the UK, she reared and released corncrake chicks, chased hen harriers, and restored peatland. She has also gained international experience, counting macaws in Peru, surveying freshwater springs in Germany, and raising kiwi chicks in New Zealand.

Meadows have always captivated her, and she has often provided advice and assistance in managing these habitats. From surveying snake's head fritillary in Wiltshire to monitoring butterfly species in Norfolk, Katie's dedication extends even to her own front garden, where she has created a mini meadow to support wild bees and other pollinators.

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