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A Nearly Perfect Reptile and Amphibian Food: Rearing and Using Earthworms

Charles Darwin said of the lowly earthworm (Lumbricus terrestris): “It may be doubted that there are many other animals which have played so important a part in the history of the world as these lowly organized creatures”….this in deference to the fact that the 50,000 earthworms that may populate each quarter acre of farmland aerate and fertilize 18 tons of soil annually!

More to the point here, earthworms come close to being a complete nutritional package for many amphibians and certain reptiles.  Although based largely upon experience, this statement is also borne out by research…one study showed that earthworms provide adequate levels of several important nutrients, including Vitamins E and A, for many vertebrate species.

A Valuable Food for Many Pets

I have raised spotted and red salamanders and green, bronze and leopard frogs from metamorphosis through adulthood on an earthworm-only diet, and use them for 50-75% of the diets of many other amphibians.  Although refused by many lizards (but relished by American and European glass lizards), earthworms are taken by most predatory reptiles.

Larger earthworms, collectively termed “nightcrawlers”, offer a healthful alternative to rodents for those keeping largely insectivorous species (i.e. basilisks, African bullfrogs), which are often erroneously fed a rodent-based diet in captivity.

I’ve also had excellent results when using earthworms as the main food for bullheads and other fishes and for certain tarantulas and centipedes. They may also be fed to marine animals, but expire and decay rapidly in salt water.

Using Earthworms

Earthworms may be broken into small pieces to feed tiny pets.  However, a whole, small earthworm is more nutritionally complete than is a piece of a larger worm. Uneaten earthworms will remain alive in aerated freshwater for up to eight hours, but decompose rapidly upon death.

Obtaining, Storing and Breeding Earthworms

Earthworms may be purchased from bait stores and commercial breeders or collected, and store well in damp sphagnum moss under refrigeration.

Earthworms breed readily in captivity but, being intolerant of temperatures much above 70F (50-65 F is ideal), are best raised in a cool basement.  They can be easily cultured in a screen-covered garbage can filled with alternating layers of moist soil and dead leaves.  Ample air flow is important, but they will wander at night if left uncovered.

Earthworms can be raised on a variety of diets.  I use dead leaves, tropical fish food flakes, oatmeal and cornmeal, into which is mixed a powdered calcium supplement.  Placing the food on the surface, beneath a layer of damp burlap, simplifies collection.

Nutrient Loading

Earthworms consume large amounts of soil while feeding, and therefore their nutritional profile will vary with collection location.  If you buy eathworms for immediate use, try to feed the worms for a day or so as described above before offering them to your pets.

Earthworms and Pesticides

In the course of tunneling through the ground, earthworms may ingest pesticides and other harmful substances.  I’ve not had any problems with wild-caught worms, but a diet of earthworms contaminated with organochlorine pesticides has tentatively been linked to the disappearance of striped skunks on Long Island, NY.  If unsure, purchase your earthworms from commercial farms.

Further Reading

For more information on using earthworms and other invertebrates, please see my article Feeding Large Insectivorous Reptiles and Amphibians.




  1. avatar

    Thanks for the helpful information. I’ve been wanting to breed earthworms for awhile now, but was unsure about what to feed them.

    My Broad-Headed skink loves earthworms! It is interesting to hear that Spotted Salamanders can be raised on a diet of only earthworms. I have a Spotted Salamander – very shy creature.

    • avatar

      Hello Sarah, Frank Indiviglio here. Nice to hear from you again. I apologize for the long delay in responding to you…an emergency surgery put me out of commission for a time.

      Thanks so much for the feedback…not all skinks will take earthworms, so your observation is much appreciated.

      When using earthworms as the sole food for salamanders, paying close attention to the earthworms’ diet is particularly important…but I doubt that will be an issue where you are concerned!

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  2. avatar

    About 3 years ago, I started a small colony of red wrigglers. I populate the tropical and forest vivariums with them.

    When I first began, I placed an old margarine container with some holes perforated near the bottom in the soil of the vivariums to feed and protect them in. In a couple of months they were out and about the area of the container.

    They now have populated many of my environments. They are great for cleaning up debris and feces of the lizards/frogs/toads.

    I often see my wood turtle rumaging through the soil, as will the water dragons. I have not had to feed my frogs and toads for a couple of years now. I do supplement the worms by burying refuse in the soil.

    Isopods have also been introduced and do extremely well in these environments.

    I am wondering if you know of any helpful bug that would do this for the drier environments? I am finding mealie worm beatles will survive and if given a food source will leave the lizards alone.

    Thanking you in advance.


    • avatar

      Hello Pat, Frank Indiviglio here. Thanks for your most interesting comment. I’m very interested in systems such as you describe, but my pleas (including to zoo curators) most often fall upon deaf ears…so nice to hear how well you are doing!

      Your earthworm idea is wonderful. Whenever time permits, I would greatly appreciate some details concerning temperature and soil depth…I have used earthworms in temperate exhibits but shy away from them in warmer habitats. Your input would be most helpful to me personally, and I’ll be sure to pass it along to those I advise in the trade and zoos.

      Charles Darwin said of earthworms: “It may be doubted that there are many other animals which have played so important a part in the history of the world as these lowly organized creatures”. This in reference to the fact that 50,000 worms turn over an estimated18 tons of soil annually (2 million may inhabit 1 acre of farmland). Yet they are over-looked as scavengers in terrariums somehow. Some of the longest-running, large exhibits I maintained were well-populated by several species…they even helped to manage bird droppings.

      The foraging behavior you have noted is something zoos are now pushing, and requiring, as “behavioral enrichment”. Very useful for your pets’ health and well-being, really makes a major difference. Keep an eye on your wood turtle –several have reported that they pound the ground with the edges of the plastron, in an attempt to drive earthworms from their burrows.

      Land snails are sometimes useful as well, I’ve had breeding colonies of several (US feral) European species, as well as slugs, do a fine job in cooler terrariums…quite interesting in their own right as well.

      In mealworm beetles you have likely uncovered the best candidate for drier situations. The larger “super mealworm” beetle “ Zophobus morio is an excellent scavenger also, especially as concerns feces, but has strong mouthparts and carnivorous leanings…debilitated pets might be at risk. I’ve had no trouble in exhibits housing robust species such blue-tongued skinks and African plated lizards, however. The larvae will not pupate without access to an area of damp substrate, but I’ve no doubt you will arrange that easily (and, like your margarine tubs, with a unique flair!).

      Isopods sometime do well in dry situations if given access to moist retreats, i.e. a buried, moss-filled container. The will leave to forage at night if the terrarium is sprayed lightly, perhaps even without such.

      I once had a colony of native beetles establish accidentally in a dry-scrub Australia-themed exhibit. I was spread thin at the time and sadly did not key them out, but they are relatives of the mealworm (darkling beetles) native to the NE USA and commonly termed “water bugs” (jet black, almost 2”, fast moving, shiny). Although favoring moist retreats, they readily foraged in the drier areas and consumed leftover salad, dead crickets and feces, and were themselves eaten by lizards and toads. I’ll check my field guides if you need further info. A number of native terrestrial beetles may also work, but many of the typical “ground beetles”, i.e. the caterpillar hunters, are carnivorous and will not clean up refuse. Please feel free to send in photos if you discover any likely candidates…if I cannot identify the insects I can easily forward the photos to someone who can.
      Thanks again, Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  3. avatar

    Thank you Frank for the awesome information in your reply.

    The red wrigglers are definately worth looking into for the warmer environments. Red wrigglers don’t need a cooler temperature. I keep a small bin under the kitchen sink year round. I run a dishwasher daily so the cupboard beneath has to spike to at least 90 F.

    But they proliferate much easier and more quickly in the actual environments. The soil base is no deeper than 2.5 to 5 or 6 inches in some spots. Temperature at ground levels would fluctuate between 65 to 85 degrees.

    I supplement the worms with kitchen refuse minus onions, garlic and citrus, dairy and meats. I also save a couple of large bins of leaves that are added in regularly to the environments. The soil base has grown but not been changed in 4 to 5 years. Extra watering will bring them closer to the surface for the reptiles and amphibians to find.

    I have a few nightcrawlers that have survived a year or so in these warmer environments. I was quite surprised to have found a few when rearranging the water area. They had been thrown in after a gardening day for immediate food but managed to escape detection until safely buried.

    I have had the same discussions with other keepers on the merits of working this way. It is difficult to convince others there are many advantages to providing these types of environments vs sterile and barren, as you have stated. Having 50 reptiles/amphibians/parrots in a small space it does wonders for controlling stress. I understand, it must be very frustrating for you.

    I have never tried slugs but will do so. I do collect snails for treats for the water dragons and basilisks here. I would love to hear how you are keeping breeding colonies, I tried for a few minutes but did not have success.

    Shame, I did not find your blog a couple of weeks ago, as there were quite a few water beetles living in the pool before it was cleaned out! gggrrrr….there’s always next year!

    I do have a plated and a bluey and will work on getting the environments set up to acheive a sustaining colony of both superworm beetles and mealie beatles.

    Again, my appreciation, of your time, attention and knowledge.


    • avatar

      Hello Pat, Frank Indiviglio here. Thanks so much for the kind words.

      That’s a very valuable bit of information you’ve uncovered…many thanks. I’ll keep it handy and will put it to good use in helping others. I have come across all sorts of earthworms in tropical zoo exhibits, but these invariably had deep soil bases (i.e. supporting live trees) and so I assumed the earthworms went deep below after feeding. Very interesting!

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  4. avatar

    One more question on earthworms…
    how many worms would you recommend that I start with as a breeding colony, should I want to pull up to 200 per month for feeding and an estimated time to acheive the goal.


    • avatar

      Hello Pat, Frank Indiviglio here.

      That’s a difficult question, as in general earthworm breeding is strongly tied to nutrition and environmental conditions (some European species, established in the USA, will only breed after a cooling off period). I’ve stocked a large plastic garbage can with 200 red wigglers (alternating layers of top soil/dead leaves) and easily drew off 100-200 month after 4 months or so. But that was a cold-adapted species (many sold under moniker “red wriggler”) that bred best at 65 F.

      Your diet sounds excellent; I’ve found the addition of a Staple Diet Tropical Fish Food to be very useful as well…can’t say if it sped growth, but the wide range of ingredients likely improved the worms’ nutrient profile.

      I’m guessing that there has been quite a lot of selective breeding going on as regards long-established bait trade earthworm species. Your breeder might be the best source of information as to ideal stocking rates and diets (assuming you are not perceived as a competitive threat!), as such can vary greatly among species and, perhaps, captive strains. If such is not forthcoming, please send in some photos of the worms…I’ll forward to an expert at the American Museum of Natural History and find out what I can.

      Keep up your fine work!

      Good luck and please keep me posted.
      Best regards, Frank Indiviglio

  5. avatar

    Great discussions here!

    Pat: I find it very interesting that you add red wigglers(Eisenia foetida I assume) to your tropical terrariums. Most times I’ve heard it is not reccomended as they will turn your terrarium bedding into worm compost.(people are instead interested in keeping true earthworms rather than compost worms like red wigglers…but a good species will need to be indentitied as you both mentioned) And at least with dart frogs they inhabitants don’t eat them. It is interesting to see that you don’t find this the case and even that you don’t change the substrate(a constant addition of fresh leaves/bedding probably helps alot).

    A good compost worm(again, not a true earthworm) to try would be the European nightcrawler(Eisenia hortensis). They are more expensive than the more common wigglers but they get much larger…2x-3x the size. Eagerly accepted by all my newts and don’t have as much of the acrid yellow secretion the wigglers do. I am in the process are starting up a worm bin with both of these species for my newts.

    another note:

    I released some Narceus americanus millipedes into a 46 gallon paludarium with some Japanese swordtail newts. They proliferate and feed on decaying plants but the newts do not eat them and they have produced lots of unsightly droppings…much of the surface is some areas was covered and I had to frequently scoop them out…so I am in the middle of removing these millipedes. Perhaps replace them with isopods. That is sort of what I worry red wigglers might do. But it would be an interesting experiment.

    Thoughts from both of you would be much appreciated!

    • avatar

      Hello Joseph, Frank Indiviglio here.

      Nice to hear from you again.

      Good points on the worms. Millipedes are good scavengers, nice to see you working with them; I’ve not run into the problem you mention, re droppings, very interesting. Sowbugs should work out just as well; I’ve never heard mention of any mess, and have had some pretty heavily stocked tanks.

      Poison frogs eat tiny millipedes; in fact they may be the building blocks for some of the toxins. Other amphibs vary, and I’m guessing the millipedes’ species makes a difference as well.

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

    • avatar

      Hello Joseph, Frank Indiviglio here.

      Congrats on setting up your outdoor enclosure; you can try to send photos to findiviglio@thatpetplace.com.

      I’ve kept anoles outdoors, and have seen large outdoor holding cages for a number of species in Florida. They usually do find enough to eat after awhile, but I always like to encourage insects with fruit, meat in a mesh bag, etc. (they really love flies) and plants as you are doing.

      A friend who lives in Louisiana says that Carolina anoles are not seen for 8 weeks or more during some winters, except for unusually warm days; a thick layer of dead leaves should be sufficient for your location, which I believe has milder winters?

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  6. avatar

    Hello Frank,

    Thanks, will definetly add leaves. Since Louisiana is coastal I’d imagine winters would be more mild than Central CA.

    I sent the photos to the aol email…the thatpetplace one does not seem to work.

    All the Best

    • avatar

      Hello, Frank Indiviglio here.

      Thanks, I see the photos have arrived via aol and will get back to you shortly.

      The anole should do fine; in Central/Western Louisiana there are stretches when the weather is in the 40’s for a time – my friend sometimes finds anoles beneath bark and leaf litter, barely able to move.

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  7. avatar

    Frank, are you still in touch with Pat Easton, I am beginning to think about breeding basilisk saw she mentioned them in one of her postings. I want to talk to someone who is actively keeping them for the tried and tested information. I also, welcome any information from yourself if you have experience in successfully keeping or breeding basilisk. specifically, the emerald plumed basilisk. Thanks, Greg.

    • avatar

      Hello Greg, Frank Indiviglio here.

      Thanks for your interest in our blog. I’m not in direct email contact with readers, but have bred Plumed and Brown Basilisks several times. In most cases, they bred nearly year-round when kept properly (78-82 F with a 95 F basking spot, plenty of UVB, large, well-planted cage, varied diet (earthworms, fish, etc)., Calcium depletion (too many clutches) was a problem in at least 2 females….Please let me know what set-up you’re contemplating and I’ll be happy to provide some specifics,

      Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  8. avatar

    Hi Frank,
    Thank you for this great information.
    We have a sheltopusik who loves her daily jumbo earthworm. She also eats super mealworms and the occasional pinkie-to-weanling sized mouse. But she craves those earthworms. Moreover, she often swallows them live and over the course of a couple hours will bring them up from her throat–or let them walk out– and pretend to let them escape, apparently for the pleasure of recapturing them.
    We get our worms from the bait shop but would love to grow our own. They live abundantly in our back yard, but there’s a problem. Our soil is rich in round worm eggs as well as a range of pests and vermin in various life stages. Our old, urban neighborhood is infested with squirrels, raccoons, opossum, cats, rats, you name it. I know the bait shop doesn’t exactly get them from a sterile lab, but it has to be cleaner dirt than ours.
    If I purchase some organic garden soil (i.e., not chemical fertilizers or herbicides added) and bake it in the oven to kill vermin, will this also make it nutrient-poor for the earth worms? Assuming leaves on the ground will have the same problems as our dirt, can you suggest plants from which we can harvest cleaner leaves from the living vegetation, that would be good substrate and gut-filler for the worms? Any leaves we should avoid?
    Thank you

    • avatar

      Hi Esther,

      Thanks for the kind words, much appreciated.

      Sounds like you’re providing a good diet. Here’s a short article on sheltopusik natural history. You can add canned snails (a major food item in the wild) if you wish, and experiment with other canned insects as well.

      Bringing food back up is not normal; sheltopusiks will overeat…I’ve never run into that behavior, but you might try cutting back on its food. No need for daily feeding; a few fast days each week are preferable. needs will depend on age and temperature, but they will adjust metabolism, to some extent, to fit food availability. Be sure that the animal is passing waste as well. Please let me know if you need more info.

      Organic soil should be fine w/o baking. No need to worry about nutrient levels; feeding the earthworms as described will take care of their needs. Leaf litter from oak, poplar, maple and any other native deciduous trees are all good; best to avoid your neighborhood, but you can collect from areas where those factors are not as much of a concern. No way to cover all possibilities, but I’ve never had problems when using leaves gathered from grounds of Bx Zoo and local semi-wild areas.

      Enjoy, best, Frank

  9. avatar

    wow frank! thanks for sharing your knowledge.
    would you think that earthworms may be an option
    for bearded dragons? i am intrigued by the thought of
    adding them as long as nutritionally it makes sense…

    • avatar

      Hi Matt,

      Thanks for the kind words, much appreciated. Unfortunately, earthworms are rejected by nearly all desert-adapted lizards…no “frame of reference”? They are taken by Fire skinks, Crocodile skinks and other forest-dwellers. I cannot recall any bearded dragons accepting them…shouldn’t be a problem with digestion, but I cannot say for sure.

      You can check out some other alternative invert species here…please let me know what you think. Best, frank.

  10. avatar

    Frank! success with my bearded dragon, he is 3 months old.
    in less than 5 minutes he ate his first, once that happened, he
    took 4 more! next question is, would is gutloading with collard
    greens and carrots enough?
    very excited beardie enthusiast!

    • avatar

      Hi matt,

      Thanks for letting me know…many do not accept earthworms. Earthworms will eat vegetables, but mainly after they have decomposed a bit..shredding them will help speed the process. Staple diet fish flakes mixed in with calcium powder, and left on the surface below a layer of leaves or burlap, is an effective gut loading diet. Be sure that decomposing leaf litter is available as well. They will probably take moist bearded dragon pellets as well…worth experimenting. Please keep me posted, enjoy, Frank

  11. avatar

    I see this is from last year but thought I’d comment anyway. If you want to collect leaves that are clean, look for oak trees. Most oaks have a tendency to hang onto their leaves for some time after they have gone totally brown. I’ve seen trees fully leafed out, all brown ! In some species leaves are still there the following spring and are pushed off by the new leaves coming along.

    So if you find an oak tree with brown leaves you can get to that isn’t near any area likely to have been sprayed with anything toxic, go and strip off as many leaves as possible. I give them a bit of a soak, maybe an hour or two, in water dosed with some baking soda [ maybe a heaped tablespoonful, to a 5 gallon bucket. The soda makes the water alkaline and helps remove a great deal of the dirt and pollution that will be on the leaves. Follow with a quick rinse in clean water, shake off and then I either hang them in small bunches by their petioles, or lay them out, to dry thoroughly. I keep them as flat as I can, it makes storing them much more space effective.

    The drying is necessary, even if you don’t wash them, if you wish to keep a supply on hand, because they are still fairly moist off a tree and would go mouldy if not well dried.

    Once dry, store in taped shut paper bags. If you wish to use plastic bags be certain leaves are bone dry, to avoid mould. I collect oak leaves mainly because they have this habit, and I can get them right off the trees instead of off the ground. They are popular with some shrimp & fish keepers too, used when leaf litter is part of the substrate habitat. In the water, the decaying leaves will grow fungal, bacterial & infusorial colonies that are useful to for feeding/newborn larval shrimp and very tiny newly hatched fish fry.

    Having read the info on earthworms, I may try to raise some wigglers under the sink, if my little floating frog will take them. She has learned to take food from tongs, so it would be nice variety for her. I plan to try fining sow bugs too to culture for her as well. She’s not keen on some bean weevils I tried, perhaps they are too small to interest her.

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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