The viper boa (Candoia aspera) is a 15-28” long, terrestrial, nocturnal snake native to eastern Indonesia and New Guinea. Their preferred habitat is rainforest, but they can also be found on coconut/oil palm plantations, where they wait for prey amongst mud and leaf litter.
Although also known as New Guinea ground boas, this snake earned the common name “viper boa” due to their distinctly viper-like appearance with a chunky body, slender pointed head, and keeled scales. However, they are boas, not vipers, and not venomous. Coloring varies between golden, orange, reddish, brown, or almost black, often with a darker blotched pattern. Males are significantly smaller than females.
Viper boas can make good pets because they’re low-maintenance and manageably-sized, but they also have high humidity needs and a specialized diet. With good care, this pet can have a 20 year lifespan.
Minimum terrarium size for viper boas
The absolute minimum terrarium size for a single viper boa is 36”L x 18”W x 16”H. Of course, larger is always better! Your snake needs enough room to stretch out fully, explore, and climb. As long as they have enough places to hide, a larger enclosure will not stress them out.
Cohabitation (keeping multiple viper boas in one enclosure) is not recommended, as viper boas are not a social species, and keeping them together is likely to cause stress.
Do viper boas need UVB?
Technically they can survive without it, but we still recommend providing appropriate UVB lighting for viper boas. UVB lighting helps provide a clear day/night cycle, provides all of the vitamin D that your pet needs, strengthens the immune system, facilitates better digestion, and other benefits. The light will not stress out your snake as long as it’s not on 24/7.
The best UVB bulbs for viper boas are:
- Zoo Med Reptisun T5 HO 5.0
- Arcadia Forest 6%
For best results, use a bulb roughly half the length of the enclosure and in a Vivarium Electronics or Arcadia reflective fixture. Position the lamp on the same side of the terrarium as the heat lamp, about 9-11” above the snake’s back if over mesh, and 12-14” above the snake’s back if not.
UVB is blocked by glass and plastic, so placing the terrarium in front of a window doesn’t count as “free UVB” — in fact it can make your terrarium too hot due to the greenhouse effect. Don’t forget to replace your bulb every 12 months!
Lights should be on for about 12 hours/day.
Best temperature for viper boas
Like other reptiles, viper boas are cold-blooded, which means that they rely on external temperatures to manage their own body temperature and metabolism. A reptile’s enclosure should offer a range of temperatures to allow them to thermoregulate effectively.
Specifically speaking, viper boas prefer an environment that is on the cooler end of the spectrum. They should have a basking surface temperature of 86-90°F, and a cool side temperature between 78-82°F. Nighttime temperatures should drop to around 75°F. Temperatures should be checked with an infrared thermometer to make sure your snake’s environment is always comfortable.
Provide heat for your snake with at least two low-wattage halogen heat bulbs, placed close together over the basking area to evenly heat the snake’s entire body. Do not use colored bulbs, as these are not as effective. However, if you need help keeping the enclosure warm enough at night, use a ceramic heat emitter or radiant heat panel connected to a thermostat.
Best humidity levels for viper boas
Viper boas need average humidity levels between 50-80% — lower during the day, and higher at night. Humidity can be measured via digital probe hygrometer, with the probe placed in the middle of the terrarium.
Increase humidity by misting your snake’s enclosure 1-2x/day with a spray bottle. Mist every evening and then again in the morning if needed. Alternatively, using a cool mist humidifier connected to a hygrostat can be helpful. Mixing water directly into the substrate also helps with maintaining high humidity. The substrate should stay moist, but not wet or soggy. There should also be a humid hide for your snake, lined with moistened sphagnum moss.
Best substrate for viper boas
Providing a thick layer of naturalistic substrate (“bedding”) will help cushion your viper boa’s body, maintain correct humidity levels, and also helps make your enclosure more attractive! We recommend the following substrates for viper boas:
- Zoo Med Eco Earth
- Zoo Med ReptiSoil
- Exo Terra Plantation Soil
- Zilla Jungle Mix
- Galapagos Blond Sphagnum Moss
Layering clean, chemical-free leaf litter on top of the substrate can also help with humidity and provides extra cover for your snake! Keep the substrate well moistened (but not soggy) to keep your viper boa happy and well hydrated.
Substrate should be at least 3” deep and completely replaced every 3-4 months. Remove poop and urates daily, along with contaminated substrate.
How to decorate a viper boa terrarium
An empty terrarium makes for a stressed viper boa, reducing its quality of life. Keep your pet entertained and engaged with its environment with the strategic use of décor items that encourage it to exercise natural behaviors!
Since viper boas are strictly terrestrial, everything will need to be at ground level. Here are some ideas for making an engaging, enriching enclosure for your snake:
What to feed to a viper boa
Viper boas are carnivores, which means that they need to eat whole animal prey in order to get the right nutrition. Here is a basic feeding schedule based on snake age:
- Juveniles — every 10-14 days
- Adults — every 21-28 days
Prey items should be around 10% of the snake’s weight and/or no more than 1.5x its width at its widest point. Although live prey can be offered, it’s best to use frozen whenever possible. Prey should be thawed in a BPA-free plastic bag in warm water, then use a pair of soft-tipped feeding tweezers to offer it to your snake.
Based on their wild diet, appropriate prey options for viper boas are frog/iguana meat Reptilinks, feeder frogs, anoles, and house geckos. Young mice/rats can be offered once in a while for variety.
Viper boas can survive without supplementation, but using them every once in a while can help prevent your snake from developing a nutritional deficiency, helping it live healthier. We recommend Repashy Calcium Plus LoD, lightly dusted on the prey item before offering.
Of course, don’t forget a large water tub/bowl for your snake to drink from and soak in! Change the water daily and scrub the bowl with a reptile-safe disinfectant weekly, or whenever it becomes soiled.
How to handle your viper boa
Reptiles generally don’t appreciate petting and handling in the same way that dogs and cats do. Viper boas have a nasty reputation as nippy snakes, but the truth is that this applies mostly to babies and wild-caught individuals. Most captive-bred viper boas with appropriate husbandry can be actually quite calm!
Here are some tips for success:
- When picking up your snake, be gentle and try to pick it up from the side or below rather than from above.
- Support as much of its body as possible.
- NEVER pick it up by its tail, as this can damage its spine!
- Keep handling sessions short at first.
- End handling sessions with the snake acting calm before putting it back.
- Wear welding gloves if you’re nervous about bites.
*This care sheet contains only very basic information. Although it’s a good introduction, please further your research with high-quality sources. The more you know, the better you will be able to care for your pet!
“Photo 118898272” by Amir Hamidy is licensed under CC BY-NC 4.0
A stuck egg is a life-threatening situation for a snake. While double-checking your humidity levels and water availability is important because dehydration does play a role in egg binding, it’s critical that you get your snake to a vet ASAP. Yes that’s a long drive, but in this case it really could be a life or death situation.
My snake is a female she came gravid with undeveloped embryos I think ones stuck inside her, she’s lost weight obviously isn’t gonna eat if she’s plugged up I’m waiting to hear back from the breeder at NERD since she came to me this way also I suddenly have no extoic vets for over 3hours away my vet suddenly retired…anyways I don’t know if I should try to massage whatever is in her ass to try an work it out I’ve never done it before and don’t wanna hurt her