That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

We all love our reptiles, but most of us loathe their lunch. Many reptiles that we commonly keep as pets are insectivores, and the most commonly available feeder insect is the domestic cricket. Yes, you read that correctly, “domestic.” Scientifically referred to as Acheta domesticus, the type of crickets sold as feeder insects have a higher protein value and a more docile nature in comparison to their wild counterparts.

Although there are a few loopholes, due to laws that govern the importation of potentially invasive species, insects which are sold as feeders in pet stores throughout the United States and Canada must be domesticated versions of their wild counterparts. The process of domestication involves strict breeding guidelines which are used to bring out certain favorable characteristics within a species, and also ensure that they (hopefully) couldn’t cause too much harm if released into the wild.

Despite their assumed hardiness, many of our reptile room customers often ask the same two questions: “What can I do to keep these darn things alive?” and “how do I keep them from escaping?”

Even though we tend to simply think of them as food for our pets, crickets are living animals themselves and these points need to be kept in mind.

 

• They need to eat: Crickets will eat almost anything. In the Reptile Room at our store we feed a special mixture of oatmeal, fish food, turtle food & dog food crumbs.

 

• They need to drink: Crickets aren’t the smartest creatures, and if you put a dish of water in their enclosure they might drown. I prefer to use an all in one cricket food/drink combo such as Fluker’s Complete Cricket Diet. This provides both water and food for the cricket.

 

• You need to clean out their enclosure: Even if you are just keeping them in an old plastic takeout container that you don’t really care about, waste products and dead crickets must be removed on a daily basis. When debris begins to break down it creates ammonia gas. After enough ammonia accumulates, the remaining crickets can quickly suffocate and die off.

 

• You don’t have to have crickets jumping all over your house: Crickets are naturally tunnel/cave dwelling creatures, therefore they are attracted to darkness. You can use this to your advantage to keep them in their container, and off of your floors. Cricket Keepers such the Exo Tera Cricket Pen are a great thing to have. They have slots on their sides where dark plastic tubes are inserted. Being attracted to the darkness, the crickets hide inside of the easily removable tubes. All you have to do is slide out the tube, shake some crickets into your pet’s enclosure, then pop the tube back into the cricket pen.

 

 

Butterworms, also known as Trevo Worms, are highly nutritious caterpillars that deserve more attention from reptile, amphibian and invertebrate keepers. They have many of the advantages associated with wild-caught insects yet lack most of the risks. Their calcium content of 42.9 mg/100g (as compared to 14 and 3.2 mg/100g for crickets and mealworms) is especially-impressive. Simple to use and store, and accepted by a huge array of species, Butterworms are in many ways superior to the more commonly-used feeders. I promoted their use throughout my long career as a zookeeper, and today would like to introduce them to those readers who may be interested in adding important nutritional variety to their pets’ diets. Please also see the articles linked below for information on other “alternative” foods such as sow bugs, sap beetles, leaf litter invertebrates, earwigs and many others.

 

Natural History

Although they resemble beetle grubs, Butterworms are actually the larvae, or caterpillars, of the Chilean Trevo Moth (Chilecomandia moorei). As far as is known, they are found only in Chile, where their diet is comprised entirely of Trevo Bush (Trevoa trinervis) leaves.

 

Butterworms are collected rather than captive-reared, and are subjected to low levels of radiation before being exported from Chile. Irradiation prevents them from pupating, thereby addressing US Department of Agriculture concerns that the species could become established in the USA. This process, and the fact that they cannot be bred commercially, renders Butterworms a bit more costly than similar insects, but I believe their value as a food source merits the extra expense.

 

Nutritional Information

Being wild-caught, Butterworms likely provide nutrients absent from commercially-reared insects. They also exceed all other typical feeder insects in calcium content (please see Introduction, above), with only silkworms and phoenix worms approaching them in this regard (some find silkworms to be delicate, and phoenix worms are quite small, but both are also worth investigating).

 

The Butterworm’s protein content of 16.2% is on par with that of crickets, phoenix worms and waxworms, and below that provided by silkworms and roaches. Fat content stands at 5.21%, which is less than (considerably so, in many cases) that of all other commonly-used feeders.

 

Please Note: The nutritional needs of reptiles and amphibians vary by species and by individual age, health, and other factors. The fact that a food is “low in ash” or “high in protein” does not necessarily mean that it is a good or bad choice for your pet. Please post specific nutrition/feeding questions below.

 

Why Use Butterworms

In addition to their nutritional value, Butterworms are readily accepted by a wide variety of reptiles, amphibians, tarantulas, fishes, scorpions, birds and small mammals. They vary in coloration through shades of yellow, red and orange, and have a distinct, “fruity” scent. I’ve not seen any research on the subject, but these qualities perhaps may make them attractive to predators…in any case, Butterworms often incite interest from reluctant feeders.

 

Butterworms range from ½ inch to 1 ½ inches in size, with the average in most containers being ¾ inch. They are far plumper than waxworms, and ideally suited for both small and larger pets.

 

These colorful, chubby caterpillars are more active than waxworms and phoenix worms, yet can easily be confined to a shallow bowl or jar lid. I’ve found this to be especially useful when keeping certain treefrogs, geckos and other arboreal species that are reluctant to feed on the ground. Butterworms may also be used to provide important dietary variety to insectivorous snakes (Smooth Green Snakes, etc.), terrestrial salamanders and others that tend to accept relatively few traditional feeder species.

 

Storage

Butterworms can be kept under refrigeration at 42-45 F for at least 4, and possibly up to 6, months. I keep my refrigerator at 39 F, and have had no problems with losses at that temperature over periods of 2-4 weeks.

 

 

Further Reading

Collecting Insects for Herp Food: Traps and Tips

Earwigs as Reptile/Amphibian Food

Bearded Dragons (Pogona vitticeps) are among the most popular of all reptile pets and a great choice for both new and experienced lizard enthusiasts.  But apparently-healthy specimens sometimes refuse to feed, or lose weight despite feeding, and there is still much confusion as to why this occurs.  My work with Bearded Dragons and hundreds of other lizards in zoos and at home has (I hope!) provided me with some useful insights into this problem.  When presented with a non-feeding Bearded Dragon, we must check our husbandry protocol (UVB, temperature, etc.) and investigate the possibility of a disease or injury. Other potential problems, such as the effects of circadian rhythms (“internal clocks”), may be less obvious, yet very important.

Is My Lizard Hibernating?

Hibernation (or brumation) is not the neat, tidy process I learned about as a child – there are varying degrees of dormancy. Depending upon where they live within the natural range, wild Bearded Dragons may experience severe winters, and will become dormant for several months each year. However, those in milder regions may remain active (please see the article linked below to read more about their natural history).

Pets sometimes cease feeding in the fall, despite being provided with 12-14 hours of daylight and high temperatures.  Although all Bearded Dragons in the US pet trade are several generations removed from the wild, the tendency to hibernate may persist.  “Internal clocks”, or circadian rhythms, can cause pets to become lethargic and refuse food during the winter.  To confuse matters further, some reptiles enter dormancy when winter arrives in their native habitats…even if it happens to be summertime in their present home!  I’ve seen this among captive Indian Gharials (fish-eating crocodiles) and other reptiles.

The Bearded Dragon Habitat

Bearded Dragons vary in their response to crowding.  Moving your pet to a larger terrarium may help, and this will also make it easier for you to establish a thermal gradient. Thermal gradients, which allow reptiles to move from hot to cool areas, are critical to good health. A 30 gallon long-style aquarium is the minimum size that should be considered for an adult…a 55 or larger is preferable.

Inappropriate temperatures will cause your lizard to slow down its feeding, and will impair digestion. An incandescent spotlight bulb should be used to create a basking site of 100-110 F. The rest of the terrarium should be kept at a temperature range of 72-85 F.

 

Like all desert-dwelling diurnal lizards, Bearded Dragons require high UVB levels. If a florescent bulb is used (Zoo Med’s models are excellent), be sure that your pet can bask within the distance recommended by the manufacturer. Mercury vapor bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well.

Diet

Wild Bearded Dragons feed upon a huge array of plants, invertebrates, and the occasional small lizard, snake or rodent. A diet comprised only of crickets, mealworms and a simple salad will not support good health long term. Offering different types of insects can also incite new interest in feeding.  We see this most commonly in chameleons, but the enthusiasm your Bearded Dragons will show for novel foods will leave you with no doubt as to their value.

Please see the articles linked below to read more about adding silkworms, house flies, sow bugs, wild-caught insects and other important foods to your pet’s diet. Studies have shown that some lizards will alter their diet in accordance with changing nutritional needs…your pet’s poor appetite may indicate that more variety is needed.

Stress

While female Bearded Dragons usually co-exist, males are intolerant of other males and cannot be kept together. If you keep your lizards in a group, make certain that each is able to bask and to obtain enough to eat. Dominant animals can frighten others even without direct aggression…merely seeing a “bully” in another terrarium may be enough to inhibit an animal from feeding. Appetite-suppressing aggression is also common among young lizards that are being raised in groups.

 

Locating the terrarium in a noisy part of the house, or where there are vibrations from machinery, may also depress appetites and contribute to other health concerns.

 

Disease, Impactions and other Health Issues

An impaction from substrate (swallowed with meals) is one of the more common reasons that Bearded Dragons cease feeding. While many have been successfully kept on sand, others seem to have problems almost immediately. The exact type of substrate used, composition of the diet, calcium intake, hydration levels and many other factors likely play a role in explaining the differences we see. Washable terrarium liners are the safest substrate option.

 

Unfortunately, highly-contagious Atadenoviruses are well-established in US Bearded Dragon populations. These viruses are spread via body contact and improperly cleaned tools; afflicted females may also pass infections along to their young. Some of the illnesses they cause, including Wasting Disease and “Star Gazing”, are accompanied by a loss of appetite and/or weight. Please see the article linked below for further information.

Internal or external parasites, and a host of other less common ailments, should also be investigated if your pet stops eating, or if it feeds but continues to lose weight. Please post below if you need help in locating a reptile experienced veterinarian.

 

 

Further Reading

 

Atadenovirus in Bearded Dragons

 

Hibernation in Bearded Dragons

 

Collecting Insects as Food for Reptiles

Frozen rodents are now widely available in the pet trade and, when used properly, are a safe food source that can save time, space and money. As opinions vary concerning proper thawing methods, I thought it might be useful to outline the procedures that are followed in major zoological parks.  Based on the human food guidelines set down by the US Department of Health and Human Services and the US Department of Agriculture, they have served me well throughout my career as a zookeeper and herpetologist.

 

General Considerations

There are two safe methods that can be used to defrost rodents intended as reptile food – refrigeration and cold water.  Microwave defrosting has certain drawbacks and should be avoided (please see below).

Frozen rodents purchased from a store or breeder should be re-packaged in clean zip-loc bags before being placed into your refrigerator, freezer or sink.  Bowls into which these bags are placed (for warming or cold-water thawing, see below) should be reserved for that purpose…do not use bowls that will also hold your own food, even if the rodents are in clean bags.  My apologies if this seems obvious, but I am continually amazed at how many people place their health in jeopardy while attempting to care for their pets!

 

Thawing Mice and Rats in a Refrigerator

Thawing under refrigeration is the method of choice in professional collections.  It requires a bit of forethought, but is very safe and requires no effort on our part (other than moving the food item from freezer to refrigerator!).

 

Thawing time will vary in accordance with refrigeration temperature (usually 35-40 F).  The USDA uses 8-10 hours per 1 pound of meat as a general guideline; a mouse can be expected to thaw in 2 hours, a rat in 4-5 hours.

 

Fail safe rule: place frozen rodents in a refrigerator for overnight thawing and use them the following day.

 

Thawing in Cold Water

This method is faster than via refrigeration, but requires periodic water changes, and leaves more room for error.  Frozen rodents in zip-lock bags are placed in a bucket of cold water for 30 minutes, after which time the water is dumped and replaced.  An adult rat can be thawed in as little as 1 hour.

 

The bags used should be leak-proof, lest harmful bacteria begin to colonize the food item.

 

Warming and Using Thawed Rodents

After thawing, rodents must be warmed somewhat before being fed to pet reptiles.  This is best done by placing the bagged, thawed rodent in a bucket or other container of warm water.  Timing varies, but plan on 10-20 minutes for a mouse in warm but not hot-to-the-touch water.

 

Use rodents shortly after thawing and warming.  Whole animals contain internal organs, previously-consumed food, and unpassed wastes, and they decay rapidly.

 

Common Mistakes

Do not thaw rodents at room temperature or in hot water (this applies to our own food as well).  Bacteria associated with disease and decay, which can be assumed present in all rodents, begin to reproduce at 40 F.  Such bacteria can take hold on the thawed, outer surfaces of a food item despite the fact that its center is frozen.

 

Rodents should never be thawed in microwaves used for your own food.  Thawing in a microwave reserved specifically for pet food is possible, assuming one can ascertain that the food item is completely thawed yet not partially cooked.

 

Rodents thawed under refrigeration can be re-frozen (if they have remained refrigerated).  Rodents thawed in cold water should not be re-frozen.

 

Today’s commercial turtle foods are, thankfully, light years removed from the yesteryear’s dried “ant eggs” (actually ant pupae). While natural foods remain important, some remarkable advances now provide turtle keepers with an important safety net, and simplify the process of providing our pets with a balanced diet. Today I’ll review some well-researched prepared diets that are valued by zookeepers and experienced private turtle owners alike.

 

Note: The excellent products described below should be used as part of a well-rounded diet….in my experience, up to 50% for some species, more or less for others. We do not, as far as I know, have long-term research concerning diets comprised entirely of prepared foods. Whole freshwater fishes remain the best source of calcium for Sliders, Painted Turtles, Snakenecks and most other semi-aquatic turtles. Depending upon the species, fresh greens, produce, earthworms and other foods may be essential as well. Please see the articles under “Further Reading” and post questions below for information on complete diets for specific turtles. Today I’ll focus on Zoo Med products, as they have an extensive product line that is backed by over 2 decades of research. I’ll cover prepared foods from Tetra, Hikari and others in the future.

 

Aquatic Turtle Food

Zoo Med’s Aquatic Turtle Food can be an important building block in the diet of a wide variety of turtles. It was formulated for Sliders, Sidenecks, and Asian Box, Spotted and Painted Turtles, but is also useful for African Mud Turtles, Spotted Pond Turtles and others. I especially like the fact that it is available in both hatchling and adult formulas, with the levels of protein and other nutrients adjusted for each.

 

ReptiSticks

This high protein (35%) floating food contains kale along with other animal and plant products, vitamins and minerals. I came to value kale as a turtle food after discussions with veterinarian co-workers at the Bronx Zoo, but find that it is not widely used by private keepers. Mixing it with the tastier foods included in ReptiSticks is also a great way to induce your “meat oriented” pets to eat their vegetables!

 

Freshwater Shrimp

Shrimp play an important role in turtle diets, but until recently only marine species have been available commercially.  However, the shrimp in Zoo Med’s Sun Dried Red Shrimp is freshwater species (the Oriental River Shrimp, Macrobrachium nipponense) and as such is a great food item for most semi-aquatic turtles. Anecdotal evidence from several of my zoo colleagues indicates that shrimp (and krill) are an excellent calcium source for a variety of turtles…and I cannot recall many that will refuse them!

 

Gourmet Turtle Food

Dried cranberries and mealworms are among the unique ingredients in Zoo Med’s Gourmet Aquatic Turtle Food, which can be used to add variety to the diets of Sliders, Cooters and similar turtles. As always, be sure to feed this and other high protein foods (37% in this product) in accordance with the needs of the species that you keep…please post below for detailed information.

 

Some Other Ideas

Zoo Med’s Floating Turtle Feeder accepts most pelleted foods, is fun to use, and will keep your turtle occupied and active.   Please see this article for more info.

 

I’ve long offered commercial turtle foods to various newts, African clawed frogs, shrimp, crayfish and hermit and fiddler crabs. When moistened, many are also readily accepted by millipedes, roaches, crickets and other invertebrates.

 

 

 

Further Reading

Feeding American Box Turtles

Slider Map and Painted Turtle Care and Feeding