I caution frog keepers against the all-too-common “cricket and mealworm only” diet. Today we’ll cover additional means of providing amphibians a varied diet that will promote longevity and breeding. The following information applies to the care of American Bullfrogs, White’s Treefrogs, Budgett’s Frogs, most toads and many similar species. Please see my other Amphibian Care Articles for details concerning Poison Frogs, Mantellas, African Clawed Frogs, Horned Frogs and others requiring specialized diets, or write in with your questions.
There is very little in the way of live invertebrates that hungry frogs refuse – I provide moths, beetles, sowbugs, millipedes, dragonfly larvae, grubs, millipedes, grasshoppers, tree crickets, field crickets, harvestmen, caterpillars and a variety of other easily-collected species.
Avoid using “hairy” caterpillars, spiders and other invertebrates that are able to bite or sting – a good invertebrate field guide should be part of every herpers “tool chest”. Brightly-colored insects are often toxic, as are fireflies; do not collect during times when your area is being sprayed for mosquito control.
I rely heavily upon earthworms in both winter and summer, buying or collecting them, and usually try to keep a colony going in my basement as well.
Traps and Canned Insects
The Zoo Med Bug Napper simplifies the collecting of moths and other flying insects; please see the articles mentioned in Part I for information on other collecting techniques.
Canned Insects such as grasshoppers, snails and silkworms are readily accepted from Feeding Tongs by many frogs, and are an important means of providing dietary variety when wild-caught insects are not available.
Calcium: Fish and Mice
A minnow or shiner each 7-10 days helps ensure adequate calcium intake for frogs the size of an adult Leopard Frog or larger.
A diet rich in pink or adult mice will cause most frogs to suffer eye, kidney and liver problems. While these aggressive predators certainly take the occasional rodent in the wild, research has shown that insects and other invertebrates form the vast majority of their natural diet.
American Bullfrogs seem to do well with a pink mouse every month or so, but do not offer adult mice – amphibians swallow their food alive, and are often injured by a mouse’s sharp teeth. Hair also leads to potentially fatal impactions.
During the colder months, or at other times when wild-caught insects are unavailable, the main portion of the diet should not be crickets, but rather a mix of earthworms (these can be used as the bulk of most species’ diets), roaches, crickets, and waxworms. Silkworms and tomato hornworms, available via internet dealers, should be offered from time to time.
I use mealworms and super mealworms sparingly, and usually select only newly-molted (white) individuals. I have found crayfishes to be an important food item for a wide variety of frogs. I remove their claws, just to be on the safe side.
You should allow insects purchased as frog food to consume a healthy diet for several days, in order to increase their nutritional value; please see the articles referenced in Part I for details.
I powder most store-bought insects with supplements, alternating among Reptivite with D3, ReptiCalcium and Reptocal. I do not use supplements when feeding wild-caught invertebrates.
You answered several questions of mine earlier concerning my Fire Belly Toads; I recently came up with a new diet for them containing meal worms and earth worms and crickets on various days;
because meal worms are hard for them to digest, I only allow them two a week and space each out between several days. they’ll each be getting once earth worm a week as well somewhere in the middle, and the rest will consist of how ever many crickets they can eat in one feeding every other day.
but before I started I had a few concerns.
I’m not sure if my Fire Bellies are just small, but both of them are only as long as, and occasionally shorter than, the meal worms themselves. my pet store owner told me they would bite them in half if needed, but as they are hard-shelled and Fire Bellies have no teeth or any other method of chewing food that I’ve seen, I don’t see how they could do that if they have very little mouths like mine do. I was curious if I could cut them in half, or if it would mess up the nutrition/ digestion process, and thus be unsafe. I know they’d still eat them and it would make me feel much more comfortable knowing they’re not so large, since with crickets they say not to feed them any much larger than the space between their eyes, and I would think the same would apply here.
for the earth worms- my pet store doesn’t care them. they told me to dig some up from outside since they’re common, but I know outside bugs are not advised, due to parasites. my impulse would say that they’re okay, because earthworms aren’t too complex, therefore surely it would be obvious if something was wrong with them; and since I’d be cutting them up because they’re so long, I’d think I’d see the parasites if there were any….. I know impulse isn’t always the best thing to go with though, so I was curious if you had any advice on the matters, as it would be greatly appreciated. ^-^
also our pet store’s supposed to be getting in some Poison Arrow Frogs soon. I’m pretty excited, but fairly sure the two can’t live together even though both have toxic properties and share a similar environment, correct?…..
thankyou for all the help. ^-^
Hello Ayme, Frank Indiviglio here.
Thanks for your most interesting note; your impulses are quite good and you are asking the questions that most people miss, keep it up!
As you suspect, frogs cannot bite or chew their food – everything they grab must be swallowed whole. An insect that is almost the size of the frog is too large, especially a mealworm; an intestinal blockage will result eventually. Always better to use several small insects as opposed to 1 large – this goes for all amphibians. Besides being hard to digest, mealworms are not very nutritious and there is evidence that their mouthparts can damage small frogs even after they are swallowed. I wouldn’t bother with them – variety is better supplied by wild insects – see below. Earthworms can form the bulk of their diet – they are one of the best frog foods. You can keep a few mealworms on hand to raise – please see this article – right after they shed, they are white in color and then are ok to use; but again no real need for them, especially since your frogs are small.
You wouldn’t actually see parasites in earthworms or any sign of illness (but a good thought); but most parasites are very specific as to what animals they attack. One carried by an earthworm would likely not transfer to a frog – I’ve used earthworms for many years in zoos and with my own collection. Pesticides are a concern with wild-caught invertebrates, but only in areas that are heavily sprayed. Moths, small beetles, pill bugs (potato bugs), millipedes and others are all great frog food – please check this article and those linked at its end for some ideas on collecting them.
Poison Arrow Frogs cannot be kept with Fire-Bellies; they need to be warmer and require tiny food in the form of pinhead crickets, fruit flies and springtails – very interesting but a lot of work; most would be stressed by the larger frogs as well. An important concept in keeping any type of animal is to avoid mixing related species from different parts of the world (Fire Bellies are from Europe and Asia, Poison frogs from S. America). One may be carrying a micro-organism that is relatively harmless to itself, but which may be cause illness when transferred to a close relative (similar to the reason people sometimes get become ill after drinking water from foreign countries when they travel; local people have a resistance to bacteria in the water ).
Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
That being said I think I like the idea of earth worms far better. since they’re larger replacing only one for each of the meal worms would probably work well to ensure a level diet that doesn’t give too much or too little nutrients? I know you can also overdose them on nutrients, calcium etc, so I want to be careful with that.
I think since they live in the dirt they should probably be safe if I get them by our side wall, since it’s a good ways from any plants that would need any sort of treatment at all and mainly consists of dirt on the side I’d be taking them from; since they stay mainly underground I think it would only be an issue if I took them from somewhere near a garden or such where the soil had absorbed treatments.
I found your article instructing on the best way to feed meal worms very helpful and I’ll have to share it with our pet store owner who loves to learn about them. ^-^
earthworms would be ideal because they’re extremely abundant and right in our backyard; I know a variety is good though so do you have any articles with advice on which bugs are best for which species? I’m always paranoid about feeding them various insects because I’m scared I’ll give them something that seems harmless and ends up being poisonous, like a lady who fed one of her lizards a lightening bug/fire fly and found her lizard dead the next morning because she didn’t realize they’re toxic to them. and as with meal worms, some insects that may be great for one species, might not be so great for another.
I was afraid that might be the case. I was also offered a large glass enclosure at the pet store for half off, granted I’d have to look it over well first, but before I even do that I’d want to make sure it was a good size. since in the wild these guys would have endless space, do you think they’d also be alright in a large space in captivity? I’d use it for my two Fire Bellies and give the Poison Arrow the slightly smaller one but since this one has a side door I don’t think it would work for them as the one likes to try to escape and encourages the other to do so as well and it would be difficult to keep an eye on both of them at once.
thankyou for all the help, I assure you you’ll hear plenty more odd questions ^-^”
and another thing I just remembered, have you seen Fire Bellies shedding? I tried to find some on youtube, but to no avail, and I don’t know anyone who owns them that I could ask.
Hello Ayme, Frank Indiviglio here.
Thanks for the feedback and the very good (not odd!) questions. We do not know too much about specific vitamin/mineral needs, but a diet based mostly around earthworms and other wild invertebrates works very well for frogs. You can use powdered supplements once weekly, 2-3 times weekly if you need to rely mainly on crickets during cold weather; I recommend alternating between ReptoCal and RetiVite.
You might enjoy this article on Raising Earthworms – useful because when they breed, you can feed small worms instead of pieces of large ones (more nutritious).
Fireflies are toxic to some species; also avoid any brightly colored insect (often a sign of toxicity, as in milkweed beetles), spiders, larger ants. Moths and small beetles that come to porch lights are great, as are harvestman (“daddy longlegs”), sow bugs, millipedes, grasshoppers, field crickets. “non-hairy” caterpillars, beetle grubs. The Audubon Field Guide to North American Insects and Spiders would be a great help in identifying the insects you find…many are interesting to keep and observe, and there’s always a chance of discovering a new species (undiscovered invertebrates pop up everywhere…).
Always good to give frogs as much room as possible…they will use the space, and the extra substrate and water helps dilute ammonia and other pollutants between cleanings, and so is a safer environment.
Frogs eat their skin as it is being shed – most peel it over their heads, like taking off a sweater, and stuff it into their mouths as it comes off – very interesting to watch, but you have to catch them in the act.
Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
I’ll definitely look more into the insect subject and earthworm breeding, thankyou ^-^
I was curious about the shedding because I’ve found one of my frogs seemingly shedding skin multiple times, but not in the manner described. no one seems to know anything else it could be, and I’m wondering if they’re having difficulty shedding due to too much or too little moisture,
Thanks for the feedback. Growing frogs will shed frequently is well-fed; constant shedding can be a sign of illness/external parasites, but you would see other symptoms – loss of appetite, etc. As long as they have water to swim/soak in, moisture is not usually a concern; Fire-bellies are highly aquatic, and do well in aquariums wth large water sections.
Good luck and please let me know if you need more info on this,
Best regards, Frank Indiviglio.
I’m worried about catching and feeding to my frogs flying insects, because I feel like they would always find a way to get out and into our house. I also realized that they could lead my frogs out in chasing them. Any suggestions or ideas?
most insects will escape if top is not secure, so be sure to use the cage clamps I mentioned last time. You can add variety to the diet by alternating between the following, which are sold onlne:
Flightless house flies
Small moths found around outdoor lights are always appreciated as well.
Thank you for all your help. These articles have been very information and I think the way I feed my frogs from now on will change, along with a few other ways I care for them. If you have written anything about crested geckos I would also love to read it.
My pleasure, Amber…pl keep me posted; I’m hoping to write about crested geckos soon, best, Frabj
Have you successfully bred earthworms ? If so, how do you do it and can i do so with a small container (20-40 liters). I have a small basement and can’t get any bigger container.
Yes…most species breed quite readily, and smaller containers are fine. Please see this article and let me know if you need further info., Best, Frank
How about Soldier fly larvae/Phoenix worms? Someone recommended those to me for my White’s tree frog with the prolapse issue (& my other frogs) saying they were soft bodied, easy to digest, low in fat, high in protein & calcium and contained lauric acid which was beneficial against cocci infection. Another person told me, however, that Soldier fly larvae were NOT easy to digest and sometimes they passed through a frog alive?? I was just going to buy some of these this weekend so could really use some good info on these insects :/
They are a great food source…ignore any site that claims they pass through alive! Digestibility depends on a huge number of factors, but in general the larvae and adults are fine as part of a varied diet. Please see this article for more info, and let me know if you need anything, best, Frank
That’s great! Definitely picking some up this weekend.
Thanks much! 🙂
I feed my american toads on a wild caught invertebrate diet as long as I can and I was wondering how edible a lot of leaf footed bugs and similar species are for american toads? For instance squash bugs (Anasa tristis), western conifer seed bugs (Leptoglossus occidentalis) and boxelders (Boisea trivittatus) among others. This time of year they are really active and easy to find, just wondering if they would be safe for toads!
Although they are probably not harmful in small amounts, most true bugs contain at least some amount of toxin. I would be weary of feeding more than a few per week.