Raising frogs from tadpoles to adults is a rewarding experience for everyone involved. It’s especially fun for children because they get to observe small, fully aquatic animals undergo metamorphosis and, eventually, start hopping on land.
One might assume tadpoles, also known as polliwogs, eat the same thing adult frogs do. That’s not the case! Tadpoles are smaller and live in water. Due to their size and habitat, tadpoles eat differently than frogs.
But don’t worry, you’ll learn all about a tadpole’s diet and, by the end of this guide, you’ll be confident knowing what to feed them! Below is a reference table comparing food sources for tadpoles in the wild and in captivity. Once finished, consider reading my guide to raising tadpoles.
|In the Wild||In Captivity|
|Algae and Plant Matter||Boiled Baby Spinach|
|Dissolved organic material (detritus)||Commercial Tadpole Food|
|Parts of dead animals (carrion)||Hard-boiled Egg Yolk|
|Insect Larvae||Other nutrient-rich, leafy greens|
A Tadpole’s Diet in the Wild
We know tadpoles spend their time in water and they’re much smaller than adult frogs. Because of their size, the potential meal for a tadpole is much smaller than that of a frog. Also, they’re still confined to the water and unable to eat land-dwelling food sources.
Tadpoles are omnivores, feeding on particles of:
- Insect Larvae
- Carrion (decaying flesh of dead animals)
- Detritus (dissolved plant matter)
In some situations, tadpoles become predators. These situations arise when there is increased competition for food. For example – hundreds of tadpoles in a shrinking puddle of water. It’s common for the bigger tadpoles to start eating the smaller ones under these circumstances.
Carrion feeding in tadpoles is well documented, too. Species have been observed feeding on the carcasses of dead animals like fish and other frogs. While the bulk of their diet consists of plant matter, eating parts of dead animals is fairly common. Tadpoles are scavengers.
The Yolk of Their Egg
Tadpoles are born into the world in small, translucent eggs. They often eat the yolk of their egg. It’s their first source of nourishment.
Even after hatching, a polliwog may stick around to finish the egg.
On a side note, some species remain motionless for several days after hatching. If you have Anura (frog or toad) eggs in your possession, don’t be alarmed if they don’t start swimming immediately after hatching. Some tadpoles float motionless for several hours or days.
Tadpoles Really Like Algae
Tadpoles eat algae like it’s going out of style. A study by Thomas A. Jenssen, published in the American Society of Ichthyologists and Herpetologists, studied the food habits of the Green Frog (Rana clamitans) before and after metamorphosis. A total of 119 Green Frog tadpoles were examined, along with water samples.
By the way, “Green Frog” is the common name for a type of frog. When I mention “Green Frog” here, it’s in reference to the species and not the color.
The findings suggest two things. One is that Green Frog (Rana clamitans) tadpoles mostly eat algae. In their samples, approximately 93.5% of their diet consisted of algae. Two, the percentage of their tadpole’s diet correlates with the food sources available in the water samples. Algae made up approximately 98% of what was available for the tadpoles to eat.
A similar study observed the feeding habits of Smith’s Litter Frog (Leptobrachium smithi) during the different developmental stages of tadpoles . In this study, algae in the guts of their tadpoles ranged between 83.32% – 90.5%, depending on their stage of development. The rest was mostly spores and detritus (dissolved organic material).
So, what exactly are algae?
Algae are sometimes considered plants and sometimes considered “protists” (a grab-bag category of generally distantly related organisms that are grouped on the basis of not being animals, plants, fungi, bacteria, or archaeans).Michael Guiry, EOL (Encyclopedia of Life)
I found this quote especially helpful because it makes sense of a complicated topic. If you’re interested in learning more about algae, click here to see the page (link goes to the EOL website).
Despite how much algae tadpoles eat, they shift from mostly herbivores (eats plants) to carnivores (eats meat) as metamorphosis begins.
Metamorphosis: From (Mostly) Herbivore to Carnivore
An interesting fact about fully-developed frogs is that they’re mostly carnivores. Very few species consume plant matter. As we just learned, the majority of food consumed by tadpoles is plant matter.
So, what’s the deal? Why do frogs go from eating mostly plant matter as tadpoles to eating mostly insects as adults?
The change in appetite is thought to take place during metamorphosis when the body has enough energy to start the process. You see, tadpoles have virtually no homeostatic feedback control until metamorphosis begins. In other words, their body doesn’t tell them when to stop eating.
During metamorphosis, the tadpole’s gut changes and becomes smaller. The digestion system that once favored algae and detritus now favors the carnivorous diet of an adult frog.
If you’re interested in learning more about this topic, follow the reference link for Melissa Bender’s research article listed at the bottom of this page.
Captive Tadpole Diet & Feeding Guide
Now that you know what a tadpole eats in the wild, let’s talk about their diet in captivity. After all, it’s the main reason most of you are here.
It’s no secret their natural environment is more suitable to support the life of a tadpole than we can create in an aquarium. Despite this, amphibian hobbyists, zoos, labs, and herpetologists have been raising tadpoles in captivity for years. And, with a little guidance, you can too.
What to Feed Tadpoles in Captivity
Feeding tadpoles in captivity can be tricky. Until the point metamorphosis begins, they want to eat non-stop. Moreover, it’s not practical to collect algae from your surrounding area. You’ll want to feed them something healthy and readily available in your area.
Listed below are some of the most popular choices:
- Boiled Baby Spinach
- Algae Wafers
- Commercial Tadpole Food
- Hard-boiled Egg Yolk
- Nutrient-rich, leafy greens.
All the tadpoles I’ve raised preferred boiled baby spinach leaves over tadpole food/pellets. Algae wafers are popular and some people occasionally feed them bloodworms. You can find most of these items in a grocery or pet store.
As far as the leafy greens are concerned, it’s best to use nutrient-dense varieties. Something high in protein and fiber. Boil the leafy greens in water until they’re soft. Let it cool before feeding them to your tadpoles. My favorite is baby spinach leaves.
I recommend offering another food source in addition to the boiled baby spinach. I’ve used commercial tadpole food with success. Other people add boiled egg yolks, algae wafers, or a cube of frozen bloodworms.
Tips for Using Leafy Greens
Baby spinach is my favorite but other nutrient-rich varieties work too. Before feeding it to your tadpoles, you need to boil it in water. This softens the leaves, making it easier for them to eat.
A clever “hack” some people do is to boil a big batch of spinach leaves, place it into ice-cube trays, and freeze it. Whenever it comes time to feed your polliwogs, simply drop a cube of frozen leafy greens into the aquarium. It will dethaw, giving your tadpoles a nice meal.
Commercial Tadpole Food
You can find commercial tadpole food in big-box stores, local pet shops, and online. They’re typically pellets or powders and they’re high in protein, fat, and fiber.
In my experience, tadpoles prefer leafy greens over pellets. I like to use these pellets (or powders) in addition to boiled baby spinach. My favorite is Josh’s Frogs Tree Frog & Toad Tadpole Food (link goes to Amazon).
How Often to Feed Tadpoles
Tadpoles are ravenous eaters. Their goal is to eat non-stop until they have enough energy to go through metamorphosis. They’re also delicate, and waiting too long in between feedings can be fatal.
Feed tadpoles 2 – 3 times per day.
In the past, I fed my tadpoles in the morning and evening. If you’re able to feed them mid-day, you can. Otherwise, they should be fine.
Tadpoles are messy, and cleaning the tank afterward can be helpful. This ties in with the next two sections.
How Much to Feed Tadpoles
Deciding how much to feed your tadpoles can be tricky. First and foremost, ensure they’re getting enough to eat. Having said that, tadpoles are incredibly messy and you can reduce the amount of cleaning by simply not overfeeding them.
Be careful not to underfeed them! Otherwise, clean any leftover food out of their enclosure around 3 hours after feeding.
The more tadpoles you have, the more food they need. In the last batch of tadpoles I raised, there were roughly 20 in total. I gave them a few leaves of boiled spinach leaves and 10 – 15 pellets each meal. The bigger they got, the more they ate. It was common to have leftover food.
Leftover food has a negative impact on the cleanliness of the water. You need to clean the water by performing partial water changes.
Cleaning Your Tadpole’s Enclosure After Feeding
One of the most important parts of raising tadpoles is keeping their water clean. You should always use clean, dechlorinated water. In order to clean the water, you must perform partial water changes when needed.
The tank will naturally get dirty over time. After all, tadpoles eat, sleep, and poop until metamorphosis. Their droppings and dissolved food matter dirty the water and raise the pH levels. When pH levels are too high, it has a negative impact on the health of your tadpoles.
If possible, reduce the amount of leftover food after each feeding or remove it after 3 hours.
You need to perform partial water changes frequently. Partial water changes may be needed as often as every day or every other day. How often you change the water depends on several factors; the number of tadpoles, leftover food, tank size, size of the tadpoles, etc.
How to Perform a Partial Water Change
A partial water change can be accomplished with two water containers and an old cup. One container should hold the new, clean water. The second container should be empty and you’ll use the cup to gently scoop the old, dirty water out of the tadpole enclosure.
The clean water should be the same temperature as the water in your tadpole enclosure. This may require you to leave the container of clean water sitting until it matches the water in the tadpole aquarium.
Remove approximately 1/3 of the dirty water from the tadpole’s enclosure.
Gently pour the new, clean water into the tadpole enclosure and discard the dirty water safely.
Frequently Asked Questions
This section will answer some of the most frequently asked questions regarding feeding tadpoles in captivity.
Tadpoles will eat fish food but I encourage you not to use it. Many brands of fish food/flakes are lower in protein and fat than that of commercial tadpole food or nutrient-rich vegetables. Feeding tadpoles only fish flakes may result in poor health and a lower lifespan. Instead, boil some baby spinach leaves, let them cool off, and feed that to your polliwogs.
When selecting lettuce, or leafy greens, you want to choose the kinds with high nutritional value. Stay away from romaine and iceberg lettuce because they offer little nutrition.
Tadpoles will eat certainly eat bread but you should not give it to them. It lacks the nutrition they need in order to begin the process of metamorphosis.
No. Once a tadpole transforms into a small, juvenile frog, its diet changes as well. Adult frogs and toads eat live insects.
Featured photo by Ken / Adobe Stock
TLDR; What Do Tadpoles Eat?
In the wild, tadpoles eat algae, plankton, bacteria, dissolved organic material, parts of dead animals, and insect larvae. Two studies revealed between 83% to 90% of the food found in the guts of 100+ tadpoles were different types of algae.
In extreme survival situations, tadpoles begin eating each other. Mostly, however, tadpoles eat plants, insect larvae, and detritus (dissolved organic material).
In captivity, you can feed them boiled baby spinach, algae wafers, commercial tadpole pellets, bloodworms, hard-boiled egg yolks, and other nutrient-dense leafy greens.
I’ve had the most success with boiled baby spinach leaves combined with tadpole pellets.
- Hofrichter, Robert. The Encyclopedia of Amphibians. Adfo Books, 2000., p. 173
- Jenssen, Thomas A. “Food Habits of the Green Frog, Rana Clamitans, before and during Metamorphosis.” Copeia, vol. 1967, no. 1, 1967, p. 214. Crossref, doi:10.2307/1442196.
- Department of Ecology and Environmental Science, Assam University, Silchar., Department of Zoology, NEHU, Shillong, Meghalaya. “Assessing Feeding Habits of Tadpoles of Leptobrachium Smithi (Matsui et al. 1999) during Different Development Stages: A Qualitative and Quantitative Study from Rosekandy Tea Estate, Cachar, Assam.” International Journal of Scientific and Research Publications, vol. 4, no. 5, 2014. IJSRP, www.ijsrp.org/research-paper-0514/ijsrp-p2980.pdf.
- Bender, Melissa Cui, et al. “To Eat or Not to Eat: Ontogeny of Hypothalamic Feeding Controls and a Role for Leptin in Modulating Life-History Transition in Amphibian Tadpoles.” Proceedings of the Royal Society B: Biological Sciences, vol. 285, no. 1875, 2018, p. 20172784. Crossref, doi.org/10.1098/rspb.2017.2784.