Frogs and toads (Order: Anura) live in freshwater habitats around the world. They’re also becoming increasingly popular as pets.
Owners must provide their frogs with the correct nutrients to survive and thrive. Feeding a proper diet requires understanding their life cycle and ecology (how they interact with other organisms and their environment).
In this article, we’ll answer some critical questions about the anuran diet, such as:
- What do frogs eat?
- What do tadpoles eat?
- How often do frogs require food?
- Which foods are most nutritious for frogs?
- How are frogs adapted to catch and eat their prey?
…and much more!
In This Article
General Frog Diet
Adult frogs are predators, meaning that they eat other animals. The vast majority of adult frogs gain little or no nutrition from plant material.
Most species feed on insects and other invertebrates.
Adult frogs can be aquatic, semi-aquatic, or terrestrial. Terrestrial and semi-aquatic frogs feed primarily on a diet of worms, insects, and arachnids.
Different foods are available in the aquatic environment, so aquatic frogs’ diets differ from those of terrestrial species. Aquatic prey items include worms, aquatic insect larvae, small fish, and fish fry.
Frogs are – for the most part – generalist predators. They will eat any animal that fits into their mouth!
Large anurans can (and will) take on small mammals, other amphibians, and even snakes!
Some frogs, such as the African clawed frog have slightly unique preferences.
Some species have unique adaptations that allow them to catch certain prey. We’ll discuss “Frog Feeding Behaviour and Adaptations” in detail later on.
Though they aren’t fussy eaters, frogs and toads do have a couple of specific dietary requirements.
1) Anurans require live food to survive.
They rely on their eyesight to distinguish predator from prey. Many species will only eat prey items that move.
Frog owners should be prepared to keep live insects in their homes.
If this thought makes you uncomfortable, then a frog may not be the pet for you!
2) Anurans require appropriately sized foods.
Frogs and toads are unable to chew their food or tear off chunks. Items that are too large for your frog can cause health complications or even death.
This information is especially important when feeding your frog live foods, as the tables are easily turned! Some insects – such as diving beetles and their larvae – will happily make a meal out of small frogs and tadpoles.
Tadpole diets can also differ significantly from those of adults. We will discuss the specific diets of tadpoles in the next section.
What Do Tadpoles Eat?
Tadpoles – also known as “larvae” – usually have a different diet to adult frogs.
Wild tadpoles tend to be more specialized than adult frogs in terms of diet. There are many general categories that species can fall into.
Some are herbivores, feeding primarily on algae. Herbivorous tadpoles may filter algae from the water column or graze underwater surfaces.
Others are omnivores, feeding on small animals as well as algae.
Many tadpoles are said to be detritivores, meaning that they feed on decomposing organic matter.
Tadpoles can also be voracious predators, feeding on small animals and their eggs. Larvae of some species can even be cannibalistic!
Fun Fact: Tadpole intestines are shaped like a long, winding coil. As they mature into frogs, their gut changes and becomes adapted for digesting large, meaty prey. In some species, the gut can shorten by as much as 75%!
In the egg, tadpoles rely on nutrients from yolk. These nutrients are enough to sustain young tadpoles for a few days after hatching.
Once they’re ready to feed, most captive tadpoles will eat specially formulated pellets. Each tadpole will require around one pellet per day for the first four weeks or so.
Tadpoles will start to undergo metamorphosis after around one month. Once their legs begin to emerge, they will require less food. Two or three pellets per week are usually sufficient.
Eventually, your tadpoles will lose their tails and become fully-fledged frogs! This transformation means that it’s time to ditch the pellets, as your frogs make their switch to whole, adult foods.
Learn all about the life cycle of a frog here.
Captive Nutrition
In the wild, frogs can eat hundreds – even thousands – of prey per day!
It would be impossible to replicate this diverse diet in captivity. Keepers must instead focus on quality over quantity.
Many “feeder” species are appropriate for adult amphibians in captivity. Each provides a slightly different balance of nutrients.
It’s important to understand the nutritional needs of your frog and which feeder species will satisfy them.
In the next few sections, we’ll help you to understand frog nutrition. We’ll run through all of the major nutrient requirements. We’ll also evaluate which feeder insects provide the highest amounts of specific nutrients.
Macronutrients
Macronutrients are the nutrients required in the largest quantities by animals. These are proteins, fats (lipids), and carbohydrates.
They provide energy and help to maintain the functioning of organ systems throughout the body.
Protein
Protein is an essential nutrient for all animals. It’s primarily used by the body to build and maintain muscle. It also provides energy and supports organ function.
As carnivores, frogs tend to have naturally protein-rich diets.
Insects usually contain 30-60% protein by weight.
The diet of an insectivorous frog should also consist of around 30-60% protein.
Most keepers don’t have to worry about their amphibians falling short on protein. Just make sure to choose appropriate foods for your species.
Fats (Lipids)
Amphibians – like humans – require fats (lipids) and fatty acids in their diet.
Fats and fatty acids provide the building blocks for important chemicals (such as hormones) and are an integral source of energy. They also aid in vitamin absorption and provide cushioning for the internal organs.
Insects consist of around 10-30% fat by weight.
Unlike birds and mammals, insects contain primarily unsaturated fats. These are particularly important for cholesterol regulation and maintaining cell structure.
An excess of lipids in your frog’s diet can lead to obesity. Obesity is a common problem among new frog owners.
Expert Tip: Some feeder species – particularly cockroaches – can lack certain essential fatty acids. A diverse diet is vital to keeping your frog healthy.
Carbohydrate (Fiber)
Frogs rely less on carbohydrates for energy (relative to humans) and more on protein and fat. One type of carbohydrate does have an essential role in the amphibian digestive system.
The main carbohydrate found in most invertebrates is chitin (the “crunchy stuff” that makes up their exoskeleton). Some frogs and toads may digest chitin for energy. More importantly, it serves as “fiber” – aiding digestion by moving other material through the gut.
Too much fiber – of any kind- can be problematic for amphibians. A diet too rich in fiber can lead to intestinal blockage.
Vitamins and Minerals
Animals require small amounts of vitamins and minerals (in addition to larger quantities of macronutrients).
These nutrients are just as crucial for long-term health, but only need to make up a small part of the diet.
Some vitamins and minerals are obtained from insect “ash.” Ash is a term used to describe all parts of the insect that aren’t protein, fat, or fiber.
Ash provides some of the necessary nutrients (aside from macronutrients) required by your frog. It’s still not enough to sustain captive frogs entirely.
All owners will need to supplement their frogs’ diet to keep them healthy.
You can do this in one of two ways:
1) Gut loading – Feeding feeder insects nutrient-rich food or supplement immediately before feeding them to your frog. The contents of their gut will be digested by the frog when eaten, providing a nutrient boost.
2) Dusting – Coating feeder insects with nutritional supplements before feeding them to your frog. Place insects in a container with a small amount of supplement powder and give it a quick shake to coat.
Calcium and Phosphorous
Calcium and phosphorus are the primary nutrients lacking from captive amphibian diets.
Both are essential minerals for amphibian and reptile health.
Healthy calcium and phosphorus levels ensure proper nervous system functioning and bone growth.
It’s vital to manage your frog’s ratio of calcium to phosphorus, as excess phosphorus can interfere with calcium uptake.
If phosphorus builds up to dangerous levels, calcium levels will, in turn, drop. Low calcium is a major cause of metabolic bone disease (MBD).
MBD is a condition in which bones become weak and brittle due to a lack of calcium. In amphibians, MBD is most often a dietary issue, resulting from a lack of calcium or a low Ca:P ratio.
To learn more about metabolic bone disease, read our article on MBD in bearded dragons.
The ideal calcium to phosphorus ratio (Ca:P) is 1.5:1.
When feeding frogs an insect-based diet, it can be challenging to achieve a healthy Ca:P.
Most insects have a low Ca:P (meaning more calcium than phosphorus). Supplementation – in the form of calcium powder – is almost always necessary for captive frogs.
Feeder Nutrition
As we mentioned earlier, there are several common “feeder” species. Each contains different amounts of essential macronutrients, along with key vitamins and minerals.
Some feeder species can make up a large part of your frog’s diet. Others should only be an occasional treat. Of course, the size of your frog is also an important factor in feeder insect selection.
Whatever you decide to feed your frog, a diverse diet is key to maintaining good health.
Among the most common feeder insects are:
- Worms
- Crickets
- Fruit flies
- Springtails
- Caterpillars
- Cockroaches
- Beetle larvae
Earthworms and nightcrawlers are good sources of calcium for frogs. They have a high Ca:P ratio. You may collect worms from the wild or purchase them from reptile stores.
Avoid using worms raised for fishing bait. These are often artificially scented or dyed using chemicals that are harmful to amphibians.
Crickets are a prevalent and versatile source of food for amphibians and reptiles. There are many different varieties – including calcium-rich options and even “micro” crickets for tiny frogs. Most crickets contain around 18% protein and have a Ca:P of around 1:9.
Springtails and fruit flies (or flightless varieties) are manageable options for smaller frogs. Fruit flies are a fairly nutrient-poor food without gut loading. Springtails are potentially higher in nutrients, though data on the subject is minimal.
Caterpillars, such as silkworms and hornworms, are also excellent feeder species. They have high Ca:P ratios. Be mindful that they do also have lower protein contents than most other feeder options.
There are many different roach species available on the feeder market. Death’s head, dubia, and discoid roaches are among the most common. Many species are too large for smaller amphibians.
Discoid and dubia roaches, in particular, are incredibly nutritious. They possess high protein contents (around 20%) and a high (1:3) Ca:P ratio.
Beetle larvae (or grubs) include mealworms, waxworms, butterworms, and superworms. Grubs are usually better offered as an occasional treat than a consistent food source. Many species are high in fat and phosphorus.
This table of feeder nutrition facts is a valuable resource for frog owners looking to learn more about feeder nutrition.
Keepers may offer mice as an occasional treat for some of the largest frog species. Rodents are high in fat and calories, so it’s vital to avoid overfeeding.
Feeding Schedules: How Much and How Often?
Feeding schedules and amounts vary based on the size and behavior of different species. Be sure to research the ideal feeding schedule for your chosen species before bringing one home.
Generally speaking, most frogs receive a limited amount of food every other day or a few times per week.
More active species, such as tree frogs, may require constant access to food. They will feed as they please, so make sure that there are always a few insects present in their environment.
Sedentary species, like Pacman and Pixie frogs, prefer larger meals less often. These species are particularly prone to obesity. For specific
information about the diets of large frogs, check out our Pixie frog and Pacman frog care guides.
There is no easy answer to the question of how much to feed your frog. Ideal amounts can vary based on age, size, and species. Again, it’s crucial to research ideal feeding protocols for your species and adjust these where necessary.
If your frog begins to gain weight rapidly, it’s likely a sign that they should cut back on the grubs!
Do Frogs Eat During Winter?
Short answer: Yes.
In the wild, some frog and toad species undergo a period of dormancy over winter. This behavior is known as brumation. The frog will usually wait out the colder months in an underground hollow or buried in an insulating substrate.
Unlike hibernating animals, frogs may emerge periodically from brumation to feed. They do this when the ambient temperature reaches a comfortable level. Frogs will then return to their dormant state once temperatures drop.
How to Feed Pet Frogs
Feeding techniques vary by species.
For many terrestrial species, live prey items should be dusted or gut-loaded and placed in the terrarium. Frogs are natural predators and will catch and eat the feeder insects over time.
It can be helpful to use a “feeding station” to keep track of small prey items, such as springtails or fruit flies. A small piece of banana will attract feeder insects, making it easier to see how many the frog has consumed.
Aquatic frogs – particularly African dwarf frogs – may need to be hand-fed. Use a turkey baster or long tongs to hand-feed these species.
Hand feeding helps to ensure that food items manage to reach the frogs. Food competition with aquarium fish can be an issue with this slow-feeding species.
You can find more information about African dwarf frogs in our comprehensive care guide.
Frog Feeding Behaviour and Adaptations
Many frogs have evolved specific adaptations to capture insect prey.
Many frogs possess a long, sticky tongue attached at the front of their mouth. Their unique tongue helps them catch fast-moving insects.
Others are “vacuum feeders,” sucking aquatic prey into their gaping mouths by creating a small vacuum in the water.
Frogs’ eyes are uniquely adapted to help them find – and consume – prey in a couple of peculiar ways.
First, the frog uses its large eyes to locate prey and assess its size. Many frogs – such as tree frogs – possess excellent night vision to find prey in the dark.
Most frogs’ eyes are highly motion-sensitive. Still, they will only attempt to eat prey of appropriate size.
Frogs may perceive moving objects that are too large to be eaten as a threat. This can trigger defensive behavior, such as the secretion of toxins.
Once a frog has captured a prey item, its eyes reveal another purpose. Frogs possess specialized muscles to lower their eyes to the roof of their mouth. This aids in the swallowing of large prey by helping to push items down the throat. And in case you’re wondering, yes, frogs do have teeth! They just don’t use them to eat in the same way most other animals do.
How Do Frogs Drink?
Like all living organisms, frogs need water to survive.
Most frogs don’t “drink” as we do. For the most part, frogs absorb water through their permeable skin.
Frogs possess a “pelvic patch” – located on their belly and thighs. The pelvic patch is specifically adapted to absorb water.
Some terrestrial frogs have adapted to use their patch to absorb water from moist soils. Frogs inhabiting drier climates also possess a waxy coating on their skin to reduce water loss.
Why Do Frogs Eat Their Skin?
Frogs shed their skin – or molt – regularly as they grow.
Their skin contains a myriad of proteins and other nutrients. Frogs eat their skins to conserve these nutrients.
More Frog Husbandry Information
Frog nutrition involves much more than just the food they eat. Also, like all animals, frogs do poop. And they produce HUGE poops. Curious?
As ectotherms, their metabolism – and ability to digest foods – can vary with temperature.
Frogs may also struggle to eat if they are under stress.
It’s vital to have a proper understanding of correct husbandry practices before bringing home any amphibian or reptile. Read on to learn on how to put that best to use, for example with a White’s tree frog care sheet – or directly go and see how a White’s Tree Frog’s habitat should be created.