American green tree frogs (Hyla cinerea) are small, smooth-skinned frogs found in the central and southeastern United States, from eastern Virginia down to Florida and as far west as Texas. Like most other frogs, they are obligate carnivores as adults, which means they eat animal-based food instead of plants or vegetation.
Green tree frogs are opportunistic predators – but they are mainly insectivores. In the wild, they eat snails, slugs, spiders, beetles, grasshoppers, caterpillars, and a wide variety of other insects. In captivity, they can be fed, earthworms, crickets, dubia roaches, small hornworms, silkworms, and other soft-bodied insects.
Green tree frogs develop in two main life stages. They start their lives as tiny tadpoles that live entirely in the water. At this stage, they eat algae, plant tissue, and detritus in their aquatic environments.
After about 12 – 16 weeks, these tadpoles will through a process known as metamorphosis and develop into the adult form green tree frogs that most people are more familiar with.
At this point, they become obligate carnivores, and will eat a wide variety of prey they can catch – but most of their diet will consist of bugs.
What Green Tree Frog Tadpoles Eat in the Wild
Green tree frogs start their lives as tiny embryos inside egg sacs. Their first food source for the developing embryos is the yolk of their eggs.
The yolk provides enough nutrition to sustain the developing tadpoles until they are ready to hatch into the water. This can take anywhere from 4 to 14 days.
After hatching, the tadpoles will have poorly developed gills, mouths, and tails – so they can not properly swim or eat yet.
For this reason, they will spend the first few days feeding on the remaining yolk of the eggs. This will provide them with enough energy to grow and develop further.
After about a few days, the tadpoles would have developed enough to start free swimming and feeding on food sources available in the water.
At this early stage, green tree frog tadpoles are almost completely herbivorous, and will eat:
- Algae
- Soft roots and leaves of aquatic plants (eg. duckweed mosses)
- Phytoplankton
- Detritus (mostly composed of degraded plant materials)
Due to a mostly herbivorous diet, the tadpoles have very long tightly coiled intestines, that make up more than half of their body mass.
Plants contain cellulose, a compound that is very hard to digest. Because of this, plant matter needs to spend more time in the digestive system. This long intestinal tract gives tadpoles more time to break down the plant matter and absorb as many nutrients as possible.
Green Tree Frog Tadpoles Become Omnivores
A few weeks into their development, the tadpoles start to grow legs, starting with the back legs. Their digestive tract will also gradually shorten.
Green tree frog tadpoles at this stage become omnivores and will eat animal protein in addition to plant matter.
They will also eat:
- Aquatic insect larvae (glass worms, mosquito larvae, etc)
- Water striders
- Zooplankton
- Small insects that fall into the water
- Worms
- Carcasses in the water
Whatever they eat, they will eat constantly. They have high energy demands because they are growing very rapidly. Growing big as fast as possible is necessary for survival, as they are an easy meal for most predators.
What Juvenile Green Tree Frogs Eat in the Wild
After about 12 to 16 weeks, the tadpoles will go through a process known as metamorphosis, in which they will transform into juvenile frogs.
During metamorphosis, the thyroid gland secretes a growth hormone called thyroxine.
This hormone triggers the tadpoles to:
- Lose the gills, and develop lungs for breathing air
- Absorb the tail into the body
- Grow strong legs for moving on land
- Remodel other organs to form an adult frog
In addition, the digestive tract shortens dramatically, and the inner lining of the remaining intestine thickens, creating many folds in the process. These folds create a very large surface for the absorption of nutrients during digestion.
Once metamorphosis fully is complete, tiny green tree frogs will leave the water and live on land.
At this point, green tree frogs become obligate carnivores, which means they stop eating plant matter and will only eat animal-based foods.
Their diet will shift away from aquatic prey and toward mainly terrestrial prey. However, since they are not fully grown yet, they can only eat small live prey.
Wild juvenile green tree frogs will eat:
- Ants, mites
- Small worms, small snails, slugs
- Spiders, termites, springtails
- Beetles, crane flies, fruit flies, and other small insects
As they grow in size, they will be able to eat slightly larger prey.
What Adult Green Tree Frogs Eat in the Wild
Adult green tree frogs are fully grown, meaning they have bigger mouths and stronger jaws. They can eat all the food they ate as juveniles, but their larger size allows them to also eat things they did not eat as juveniles.
Here’s a list of things that make up an adult green tree frogs diet in the wild:
- Termites, ants, flies, mosquitoes
- Pillbugs, ticks, mites springtails
- Spiders, centipedes, millipedes
- Slugs, snails,
- Small worms
- Caterpillars, & other tiny insect larvae (such as maggots, moth larvae, grubs, etc)
- Beetles, stinkbugs, moths, butterflies, bees
- Flies, grasshoppers, tree crickets, and a wide variety of other insects
Green tree frogs are very opportunistic and will eat almost any prey small enough for them to swallow whole. They are frequently encountered near porch and patio lights during warm, wet weather – eating moths and other insects attracted to the light.
One study found that they select prey not by their size, but according to their activity levels, with the most active prey being the most frequently eaten.
According to the same study, nearly 90% of prey eaten by green tree frogs were actively pursued, with the other 10% being insects walking or close enough to be snatched up by the frog’s tongue.
As earlier mentioned, green tree frogs are insectivores, so bugs will make up the majority of their diet.
A study at Arkansas State University analyzed the stomach contents of 120 Green Tree Frogs, collected between May 1956 and October 2014 in Arkansas.
It was found that beetles and arachnids were the main prey item eaten, followed by flies (of the order Diptera), and then bugs (of the order Hemiptera).
Plant matter was also found in the stomachs of several frogs, suggesting that green tree frogs occasionally ingest plant matter when actively foraging.
However, this ingestion is purely accidental, as these frogs are obligate carnivores as adults – and do not eat plants.
What Adult Green Tree Frogs Eat In Captivity
Captive green tree frogs can eat all the food they would eat in the wild. The only reason they have a different diet is that most hobbyists cannot easily obtain the wide variety of prey these frogs eat in the wild.
So they are limited to only prey items they can purchase or culture on their own.
However, even in captivity, it’s a good idea to keep your green tree frogs diet as close to its wild diet as possible. This means you have to feed it live prey.
Feeder crickets seem to be a favorite among many green tree frog owners. It is important to gut load the crickets & dust them 2 – 3 times per week, to make them more nutritious (more information on that is below).
Here’s a list of things you can feed a green tree frog in captivity:
- Crickets, dubia roaches, flightless fruit flies
- Mealworms, wax worms
- Silkworms & hornworms
- Nightcrawlers
Green tree frogs are not picky eaters, and will readily accept most soft-bodied invertebrates. Crickets can make up a majority of their diet. However, the key to a healthy green tree frog is a varied and nutritious diet, so remember to switch up the food items offered every few feedings.
The only problem with certain feeders, for example, dubia roaches and mealworms – is that they tend to burrow under the substrate of the frog’s enclosure, – so they will not be visible and the frog can not eat them.
To get around this, you could try putting them in a small ceramic dish. Doing this will prevent them from moving around too much (and burrowing), and it will also make them more visible to the frog, so it can eat them.
Be careful to feed the proper size prey for your frog’s size. A good rule of thumb is that a cricket should never be larger than the distance between the frog’s eyes, or the distance from its eyes to its nose.
If you want to feed your frog mealworms, it’s a good idea to only use the ones that have just shed, and still have soft bodies, as the hard exoskeleton of mature mealworms is very hard for green tree frogs to digest.
As for fruit flies, I recommend Hydei fruit flies as they are considerably bigger than the Melanogaster fruit flies and make a richer meal for your frog.
Also, IT IS NOT RECOMMENDED to feed red wigglers (Eisenia fetida) to captive frogs. This is because they exude a noxious fluid that contains a toxin known as Lysenin – which is poisonous to many animals.
Since these worms are foul-tasting, some frogs will actively spit them out instead of swallowing them. If the frog somehow accepts the worms, it may be harmed by their toxins.
Can You Feed a Captive Green Tree Frog Wild Bugs?
You could feed your green tree frog wild-caught bugs. Just be 100% sure they are from a clean area that’s free of pesticides or other chemicals. Avoid feeding bugs that can sting or bite, such as large spiders, hornets, bees, etc
However, it is generally not a good idea to feed captive frogs wild bugs or other wild prey. This is because wild insects may carry diseases and parasites that your frog is vulnerable to.
Also, wild bugs in a seemingly clean area could be carrying pesticides they picked up from another area.
Gut-Loading & Nutrient Supplements
Captive-bred feeder insects are often raised on a cost-conscious diet that is meant to help them grow quickly. This means they are not as nutritious as wild insects that eat a wide variety of vitamin and mineral-rich food.
If your frog is given a low-nutrient diet, it could develop health problems such as metabolic bone disease – which is a fairly common issue in captive amphibians.
For this reason, it is important to increase the nutritional value of the food you give to your frog.
This is mainly done in two ways: dusting, and gut loading.
Gut Loading
Gut loading is the process by which feeder insects are fed nutrient-dense foods at least 48 hrs before they are offered to the frog. The intention is to pass those nutrients on to the frog when the insects are eaten.
The process is simple
- Give your feeder insects nutrient-dense foods, such as fresh vegetables with lots of vitamin C.
- After eating this food, the feeder insect will be much more nutritious and pass the nutrients on to the frog when they are eaten.
Dusting
Besides gut loading, another way to ensure your frog gets all the vitamins and minerals it needs is by dusting its food with high-quality powder calcium and vitamin supplements.
Most hobbyists use commercially manufactured supplement powder specifically designed for reptiles and amphibians.
The process is simple:
- First, add a small pinch of supplement powder into a small container such as a cup or an empty cereal container. The powder should only be enough to lightly dust the insects.
- Place one feeding’s worth of feeder insects in the container
- Gently shake the container so the supplements lightly coat the insects
- Once finished, you can offer the dusted insects to your frog
It is important to know what calcium formula is right for your pet, whether it be no D3, low D3, or high D3.
Since green tree frogs are nocturnal, they are not going to metabolize the D3 from the sun – but will instead absorb it from their diet. For this reason, it’s recommended that you use a calcium supplement that is high in D3.
It’s a good idea to alternate between a calcium a multi-vitamin powder. If you dust with a calcium powder, next time remember to dust with a multi-vitamin powder instead, and vice-versa.
Avoid using a calcium supplement with added phosphorous, unless specifically directed by your veterinarian, since this can promote kidney disease.
How Much & How Often to Feed Your Green Tree Frog
Generally, adult green tree frogs will have to be fed every two or three days, while young green tree frogs will need to be fed every day or two.
However, this is not set in stone. If an adult does not eat not each much during feeding sessions, it may have to be fed every other day.
In addition, the enclosure’s temperature will determine the feeding frequency.
If the temperature is low, your green tree frog will have a slower metabolism and be less active, so it won’t need to each much.
At warmer temperatures, your frog will have a much faster metabolism and will need to be fed much more frequently (every other day).
Regarding how much to feed your green tree frog, the general rule is to only offer as much as the frog can eat in a 20-minute feeding session.
Over-eating usually isn’t a problem with this species, so this can be learned with a little bit of experimentation. Use personal judgment to ensure most of the food offered is being consumed.
Keep a close eye on the frog so you can adjust their diet accordingly. If your frog is overweight, consider reducing the number of food items you feed them each meal. Likewise, if they’re underweight – you need to feed them more food items per feeding or feed them more times per week.
How Long Can a Green Tree Frog Go Without Food?
Generally, healthy adult green tree frogs can go for as long as two weeks without food if the environmental temperatures are low, and the frogs are not very active. Juvenile green tree frogs can not survive long without food as they are still growing and have higher energy needs.
However, this isn’t to say you should test the endurance of your frog.
In most situations, it’s a good idea to feed your green tree frog at least two-three times per week.
What Green Tree Frog Tadpoles Eat In Captivity
Green tree frog tadpoles have a different diet from the metamorphosed adults. During the first few days after they hatch, they will absorb the remaining yolk around them so feeding won’t be necessary.
Once the tadpoles begin moving around and free swimming, you can start feeding them boiled and finely chopped vegetables such as:
- Lettuce
- Broccoli
- Baby spinach
- Zucchini
Apart from vegetables, you can also feed:
- Algae wafers
- Aquatic frog and tadpole food
When the tadpoles start to grow legs and lose their tails, you can start feeding them late-stage tadpole food, as well as fish flakes with animal protein.
Like the adults and juveniles, green tree frog tadpoles need a varied diet so it’s important to rotate their diet. You can use both vegetables and commercial food to give greater variety.
The tadpoles have to be fed daily, but be careful not to overfeed. All food should be eaten within 3 – 4 hours. If there is excess food in the water, it should be removed or it will leave a film on top of the water.
What Juvenile (Baby) Green Tree Frogs Eat In Captivity
When the tadpoles go through metamorphosis (in about 12 – 16 months) and transform into froglets, they become obligate carnivores – so they have to be fed small live prey.
Since they are not fully grown yet, they have to be fed a smaller version of their adult diet. The food has to be gut-loaded and dusted with supplements.
Baby green frogs can be fed:
- Pinhead crickets
- Wingless fruit flies
- Springtails
- Small mealworms
As the froglets grow in size, they will be able to eat larger things.
The froglets have huge appetites so they have to be fed every day – and as a general rule, their food should be dusted more often than an adult’s.
Be careful to feed the proper size prey for your frog’s size. A good rule of thumb is that a cricket should never be larger than the distance between the frog’s eyes, or the distance from its eyes to its nose.
When feeding larger insects to your pet, try to make sure the insects have recently molted, as an insect with a large, hard exoskeleton is difficult to digest and may cause impaction.
What Human Foods Can a Green Tree Frog Eat?
Froglets and adult green tree frogs are obligate carnivores and are instinctively attracted to movement while hunting for food. For this reason, they will not eat the vast majority of human food.
Humans do not typically eat live food and tend to cook most of their food, so human food will not even register as food to most frogs, including green tree frogs. If you try to offer human food to a green tree frog, it will not eat it and will go hungry.
How to Feed a Green Tree Frog in Captivity
The easiest way to feed a green tree frog is to simply dump the food into its enclosure and let the frog have its fill.
However, some frogs, especially those that are still getting used to a new place may be shy and reluctant to eat. In this case, you could entice the frog to eat with the use of some feeding tongs.
Use the tongs to gently hold the food item, then rub it near the nose of the frog. Once he sees it, he will grab it and eat it.
Also, it’s a good idea to tong-feed when you want to give your frog certain feeders (such as mealworms, dubia roaches, or earthworms) that aren’t very active or tend to hide under the substrate.
Why Isn’t My Green Tree Frog Eating?
1. It Is Still Getting Used to a New Place or Is Shy
The most common reason a frog won’t eat is that it is under stress, or still getting used to a new place. This is a very common problem with newly acquired frogs
To remedy this, try hand-feeding the frog with the help of feeding tongs/tweezers. Use the tongs to gently hold the prey item, and wiggle it in front of the frog to entice it to eat.
If this does not work try moving the frog to a dark room, and leave it alone to relax and settle down for a while. In the wild, green tree frogs are nocturnal creatures, so they will be more active in the dark.
2. You Are Feeding the Frog at the Wrong Time of the Day
Despite being nocturnal, green tree frogs can usually eat at any time of the day. However, sometimes individual frogs may have their own feeding preferences.
If your green tree frog won’t eat during the day, try feeding it just before the lights turn off in its enclosure. Or, If you’re not using a UVB light, during the evening time as the sun is going down.
3. The Prey Item Being Offered Is Too Big
Another reason a green tree frog may reject food is that the prey item you are offering is just too big. Remember, frogs do not chew their food, so they will not eat anything they can now swallow whole.
As a general rule, never offer a frog any prey larger than the distance between its eyes.
4. It Is Not Accustomed to the Food Item Being Offered
Another possible reason a frog may reject food is that it is not used to eating the food you are offering. Try switching the food item being offered. Most green tree frogs will readily accept live crickets and other soft-bodied invertebrates.
5. The Environmental Temperatures Are Low
Remember, frogs are ectothermic (cold-blooded animals). When the temperatures are low, they will have a lower rate of metabolism, and be less active, so they won’t have the biggest appetite.
This is perfectly normal, and the frog will have a much better appetite when the temperatures are warmer.
Common Feeding Mistakes
There are a few common mistakes many new frog owners make when feeding their pets.
Using Dead Bugs
In the wild, frogs are ambush hunters that are attracted to prey by movement (motion). For this reason, green tree frogs won’t eat dead bugs. If you offer your green tree frog dead bugs, it will most likely ignore the food and starve. You should only offer live bugs and other prey items.
Using the Wrong-Sized Feeder Insects
Frogs do not chew their food but rather swallow it whole. Feeding a tiny frog a disproportionately large insect could lead it to choke.
Never give a frog anything larger than the distance between its eyes. The bigger the frog, the larger the prey it will be able to eat.
Forgetting to Gut Load Insects
As mentioned earlier, captive-bred feeder insects do not contain as many nutrients as wild insects. They are often raised on a cost-conscious diet that is aimed at making them grow quickly and keeping costs low.
Forgetting to gut load or dust insects before feeding them to your green tree frog means the frog will not get all the nutrients it needs. This nutritional deficiency can lead to serious health problems, and could even be fatal.
Not Using a Varied Diet
Different food items have different nutrients. Not giving a green tree frog a varied diet means it will not get the right variety of nutrients it needs and may end up weak and malnourished.
Switch up the food items offered to the frog every few feedings so it gets a nutrient-rich diet.
Feeding Food With a High-Fat Content Too Often
Captive frogs are not very active animals, so they do not burn off calories. This means giving a captive green tree frog high-fat food (such as wax worms) too often may lead to obesity.
Obesity can then lead to many health problems. For this reason, it is important to limit food with a high-fat content to only an occasional treat.
Overfeeding/ Underfeeding
Overfeeding a frog can lead to obesity, which could lead to several health problems. Alternatively, underfeeding means the frog will be undernourished and have poor health.
Common Questions About Green Tree Frog Diet
Can American Green Tree Frogs Eat Mealworms?
Green tree frogs can eat mealworms but they are not the best food option for your frog.
Mealworms are high in fat, have little meat, and have a hard exoskeleton that is difficult to digest. Silkworms or hornworms are a better choice as they have more meat and a soft exoskeleton, that is easy to digest.
If you want to feed your frog mealworms, it’s a good idea to only use the ones that have just shed, and still have soft bodies, as the hard chitin exoskeleton of fully-formed mealworms is very hard for green tree frogs to digest and can led to impaction.
Can Green Tree Frogs Eat Fruit?
Green tree frogs are generally obligate carnivores as adults and do not eat fruit or any other plants. Their digestive systems are suited for digesting animal-based foods, rather than plants matter.
Can Green Tree Frogs Eat Worms?
In the wild, green tree frogs will eat any worms they can catch – and In captivity, they will readily accept earthworms.
It is not recommended to feed red wigglers (Eisenia fetida) to captive frogs. This is because they exude a noxious fluid that contains a toxin known as Lysenin – which is poisonous to many animals.
Can Green Tree Frogs Eat Large Crickets?
Large green tree frogs can eat large crickets. A good rule of thumb is that a cricket should never be larger than the distance between the frog’s eyes, or the distance from its eyes to its nose.
Can Green Tree Frogs Eat Superworms?
Large green tree frogs can eat superworms. Like mealworms, it’s a good idea to only use the ones that have just shed, and still have soft bodies, as the hard chitin exoskeleton of fully-formed superworms is very hard for green tree frogs to digest.
Can Green Tree Frogs Eat Hornworms & Silkworms?
Green tree frogs can eat hornworms or silkworms. In fact, they are make a better feeder than mealworms, as they have as they have more meat and a soft exoskeleton, that is easy to digest.
Can Green Tree Frogs Eat Lettuce or Other Vegetables?
Green tree frogs do not eat lettuce or any other vegetables. They are obligate carnivores and will only eat animal matter to obtain the nutrients they need. However, green tree frog tadpoles are mostly herbivorous and do eat lettuce and other vegetables, such as spinach, broccoli, lettuce, and Zucchini.
What Do Green Tree Frog Tadpoles Eat?
Green tree frog tadpoles are mostly herbivorous and eat algae, the soft roots, and leaves of aquatic plants, plankton, and detritus.
As the tadpoles grow their intestinal tract will gradually shorten, and they will also eat animal protein such as aquatic insect larvae, small insects that fall into the water, worms, and carcasses in the water
What Do Baby Green Tree Frogs Eat?
Newly metamorphosed green tree frogs eat ants, mites, small worms, small snails, slugs, spiders, termites, springtails, fruit flies, and other small insects in their environments.
Sources:
Thigpen, C. S.; Dodson, H.; and Trauth, S. E. (2016) “Food Habits of Green Tree Frogs (Hyla cinerea) from Arkansas,” Journal of the Arkansas Academy of Science: Vol. 70, Article 38. DOI: https://doi.org/10.54119/jaas.2016.7030 Available at: https://scholarworks.uark.edu/jaas/vol70/iss1/38
Dawn M. Trainor (2012) American Green Tree Frog Hylidae cinerea. Specialized Care for Avian & Exotic Pets In conjunction with Pet Supplies.
University of Florida. WILDLIFE ECOLOGY AND CONSERVATION DEPARTMENT. Green Treefrog (Hyla cinerea).
Animal Diversity Web, University of Michigan Museum of Zoology
AmphibiaWeb. University of California, Berkeley, CA, USA.
