Captive Care of the Rubber Boa
As Rubber boas are small, large cages are not necessary. A five or ten gallon aquarium with a very secure lid is generally adequate. Any small hole or crack in which the boa can get its head through is an easy escape route. I can't stress enough that these snakes are excellent escape artists. I have conversed with numerous people who have caught one, only to find that it escaped within a day or two. The cage must be secure. Multiple boas may be kept together in a larger cage without any problems, as in the picture above. At the time of the photo, the four foot by two foot cage housed six individuals. As long as all individuals are healthy, and sanitary conditions are maintained, no ill effects occur. In fact, they often ball up all together as they would do when hibernating in the wild. See Multiple Rubber Boas in a Cage for further discussion.
If any one aspect of the keeping of Rubber Boas must be stressed, it is that they must not be kept too warm. Rubber Boas do not require the warm conditions that many other snakes prefer. Room temperatures are generally adequate. Normal cage temperatures should be kept in the low 70's to low 80's. Individuals can digest meals as low as 60 degrees (not recommended), with closer to 80 degrees being optimal. They will seek to escape any basking spot that reaches up to 90 degrees. When digesting a meal or carrying young, a low wattage light bulb, or undertank heater may be provided to create a heat gradient within the cage so the snake can choose the proper temp to bask in. Use a thermometer in the cage to be sure the temperature does not get above the high 70's to mid 80's. In the picture above, a 25watt red bulb was used in to provide a basking spot in the low 70's during early spring. The cool end of the cage ranged from 50 at night, to 65 during the day. As spring progressed, I replaced the 25watt bulb with a 40watt bulb. Depending on time of year, ambient temperatures, and distance from the basking spot, different size bulbs will be necessary.
If not digesting a meal, or incubating young, it is best to drop the temperature to 75. Of course this may be difficult in warm climates. Techniques to keep them cool in hot weather include: keeping them in air conditioned living space, place cage on concrete floor that does not heat up as much, or keep them in a room with the window open at night, and closed up during the day. If kept too warm they may be come agitated and musk when you try to pick them up, and will be at risk for dehydration and excessive weight loss. It may seem strange to those that are used to keeping tropical snakes, but a Rubber Boa should feel cool to the touch (but not cold) when picked up.
Hibernation is not necessary except in preparation for breeding. Hibernation should start around late October or early November with temperatures ranging from 40 to 50 degrees until March. They generally do not have any problems as long as the temp remains above freezing. Rubber Boas have been found wandering their cage at temperatures as low as 40 degrees although usually dormant at this temp.
Being primarily nocturnal and fossorial, Rubber Boas do not require any special lighting such as UV. Access to natural light from daytime sunshine entering a room is adequate. But never place an aquarium where it will be exposed to direct sunlight. Temperatures can quickly reach dangerous levels to the snake, and it may have nowhere to escape the heat. If a light bulb is provided as heat source, it should be set to mimic daylight cycles so as not to interrupt normal nighttime activity. If the snakes are being kept in an area that is too cold at night, and heat is necessary, a low wattage red light bulb may be used. The red light is not as disruptive to nocturnal animals.
As suggested for other snakes, do not use cedar shavings as it is toxic. Aspen, or other small wood chips are suitable. Sand, artificial turf, sterile soil, and paper are suitable alternatives. Small wood chips, reptile sand, or other absorbent materials are good in that feces may be easily scooped up and discarded. Paper is handy in providing an easy to clean cage lining, but do not provide a comfortable home similar to natural settings. In choosing the substrate, consideration should be given to the possibility of accidental ingestion of substrate that could cause damage to mouth or impact the digestive system. In the wild, small amounts of material (grass, dirt, etc) are normally ingested when eating. It becomes a problem when large pieces, sharp objects, or large quantities are ingested along with the prey. This could cause damage to the snake resulting in death. If the substrate used is not appropriate for eating on, move the snake to a clean location when feeding.
A choice of hiding places should be provided. Rubber boas enjoy pieces of bark, moss, and hollowed logs. Even an overturned dish or board propped up on a small rock, would be appreciated by the snakes. Substrate deep enough to burrow in is recommended by some keepers but not necessary if adequate hide boxes are provided. Much of their time will be spent in hiding under these items, and are an important part of their housing. At times, I have even used a cut off leg of denim jeans as a hide for the boas to climb in and under. A moist hide box may be provided also by cutting a hole in the lid of a small rubber maid container and placing moist paper towels (change frequently) or moss inside. Whatever is used as hiding spots, it is preferable if it is snug. A slight squeze is preferred to a vast open area.
Live pinky or fuzzy mice are the best food source, although frozen/thawed are just fine. Larger females may also eat hoppers or small adults. (See Happy Herps webpage for visual descriptions of mouse sizes.) Only the largest of females may eat (small) adults, which should NEVER be placed in the cage live. Rubber boas do not have high nutritional requirements, but care should be given to choose quality mice from a reputable breeder, or assure that your mouse colony receives adequate variety for complete nutrition. Rubber Boas do show a significant preference for wild mice over lab mice. Wild caught boas, or babies that have never eaten lab mice may be difficult to switch to lab mice, but it can be done.
A Rubber Boa that is comfortable in its surroundings is generally not a finicky eater, but occasional reluctance to feed may be encountered. If you have difficulty, consider the following:
- Newborns generally do not eat in the time period between birth, and emergence from hibernation in March. (See Frequency section below)
- As with all snakes, smell is an important part of eliciting a feeding response. Try placing some mouse nesting material with the food to increase smell.
- Another technique for exciting snakes through smell is braining. I find myself doing it often to entice a snake to feed. Go to Happy Herps feeding guide for further guidance on how to brain pinkies, and other methods for reluctant feeders.
- If frozen mice are being offered, be sure they are warmer than room temperature so that the snake can sense it, and it is actively giving off aromas. A good way to do is with warm water. (as so many have found out, a microwave just does not work!) I place the mouse in a ziplock bag, and submerge it in warm water.
- Also, it may be helpful to wiggle it a little bit as if alive when the boa begins to nose and nudge it. Usually this will entice the snake to grab it.
- Rubber Boas really seem to like finding their food. A pinkie put in their face may be ignored, but one tucked in the corner of the cage, under a piece of bark will be found, and is more likely to be consumed.
- Some wild caught boas will eat right away after capture, while others seem to want a period of time to settle in prior to eating. This can range from just a week to several months.
- A wild caught boa who has never eaten lab mice will rarely refuse baby microtus (voles) or peromyscus (deer mice See info about peromyscus ). If one can be obtained, or their nesting material, it can be used for "scenting" of a lab mouse pinky. Then a normal, unscented pinky can be chain fed right after to introduce them to the new food item. See my Chain Feeding page.
- I have had great success in getting the finickiest of eaters to take lab mice by first washing the pinkie. To wash it, rinse it in warm water, rub just a little bit of diswashing soap (I use Ivory) on it, and rinse it off throughly. I also brain it, and place it in the snakes cage overnight and do not disturb untill morning.
Periods of fasting, either by choice or circumstance are common for Rubber Boas. Unlike larger snakes like Kings or Corns, Rubber Boas are not able to eat any mouse they encounter during daily activities. Rather, they must search long and hard for a mouse nest with the right size babies. As such, they do not eat as often as many other captive species.
When born in the early fall, babies generally do not have a chance to eat before entering hibernation. The first meal may not be eaten until nine months after birth. This is normal, and easy for them to handle as long as temperatures remain cool (low 70's during active times, and 40-50 during hibernation). You may offer them pinkies, but do not expect newborns to eat. Many people have success starting newborns on brained pinkies. However, I would recommend that if a baby is obtained, keep it hibernated until March at which time it may be fed newborn pinkies. For further information regarding the feeding of babies and proper sized meals, see Juvenile Feeding Guide.
Males fast during courting, and only rarely will eat between the time of emergence from hibernation until courting begins. Once courting has begun, they will not eat until courting is completed in late Spring. This means that males normally fast for six to seven consecutive months each year (from start of hibernation to end of courting). Keep in mind though, the temperatures are cool during most of this time. Except for late spring daytime, temperatures are almost always below 70 where they live, and thus reserves are not used very fast. If a male is kept at high temperatures (85) for extended periods during the spring after emerging from hibernation, his reserves will be unnecessarily used too fast. Most of a male Rubber Boa's food requirements for an entire year are met from June to August.
Females will eat after coming out of hibernation, but if bred will generally stop eating once ovulation takes place, and will not eat again until the young are born in the fall. Those females from areas where food is plentiful may eat while gravid, but likely will regurgitate the meal within 24 hours. Females from other populations in marginal habitat where food is scarce seem to have developed an ability to digest through most of the gestation period.6
When recently moved, or introduced to new surroundings, it may take several months before becoming used to a new home, and may not eat until comfortable. Be patient, and allow it time to adjust. It will likely refuse to eat until it has fully settled in. This may take one week, or several months. But when it needs to eat, it will. A healthy adult in captivity may go up to one year without eating if temperatures are kept low (70's or lower). The higher the temperature, the quicker a fasting snake goes through its reserves.
To mimic natural conditions, several pinkies or fuzzies should be offered at least monthly. Overfeeding is generally not a problem, and more frequent meals may be offered if desired. Allow the snake to eat all it wants each time. But do not be concerned if your Rubber Boa decides to go without food for a couple months at a time (unless you are keeping them too warm).
The best method for Rubber Boas is to place the mice in the cage near the snake, under a hiding spot (as if in a real nest), and leave it be. When I am feeding, I place two, three, or four, or may be even five baby mice (depending on snake and prey sizes), and a little bit of nesting material outside of where the Rubber Boa is currently hiding. Then I cover the mice with a piece of bark, propped up board, or even just a piece of denim fabric. I will watch for several minutes as the snake will usually smell the prey, seek it out and begin eating. If not, I leave the room and check back in 1/2 to one hour. If the snake is still not eating, but has eaten recently so is in good shape, I will go ahead and remove the prey to try again at a later date. But if it has been several weeks since last feeding, and the snake is not in a normal fasting period such as winter, males in the Spring, or females that are incubating eggs, I will leave the mice in the cage with the snake all night. Usually they will be gone the next morning. If not, there is no need to worry. Try again a few days later. Click Here for pictures of this method.
Once a Rubber Boa has been in captivity for an extended period of time, and has eaten regularly, it can be offered individual meal items and will take them immediately. Two females I have that have been in captivity for at least a decade each, will eat mice right out of my hand without any hesitation. Yet, as long as my hands do not smell like food, and they are handled regularly, they do not come to associate the hand with food, and strike as some snakes would.
For further information and illustration of methods for feeding Rubber Boas, see the Feeding Guide page.
Clean water should be provided in a dish at all times. Rubber Boas often enjoy soaking. The water must be changed often to avoid ingestion of fecal matter. In addition to a water dish, regular soakings are recommended. Each snake should be soaked once a month during hibernation by placing in a jar (with secure lid that has ventilation holes) with 1/2-1 inch of cool tepid water to soak for fifteen to thirty minutes. (This will not abnormally disrupt their hibernation. Females MUST be hibernated to breed, yet many years of this practice has not adversely affected female ability to produce young. In the wild, Rubber Boas normally hibernate in relatively moist conditions, and may be flooded at times.) You must keep in mind that water that feels warm to our hand, is probably somewhere above 90 degrees, which is hot to a snake at 75 degrees, and even hotter to a hibernating snake. Soakings during active periods should be increased twice a month. But do not soak after eating until the meal has been passed to avoid ingestion of fecal matter that may be passed in the water. (A nice warm bath is a quick way to get a snake to poop.) When the snake is ready to shed, an additional soaking will help in removal of the old skin. As well as providing the snakes an opportunity to drink, soaking may aid in controlling mites. Damp hiding spots also aid in keeping them hydrated, but are not absolutely necessary if water and soakings are regularly provided. The skin of a well hydrated Rubber Boa simply looks so much better than one that is slightly dehydrated. I beleive that most Rubber Boas in captivity are slightly dehydrated.
Most Rubber Boas are glad to be picked up and handled. They enjoy the warmth of your hands. But sometimes when you first touch your Rubber Boa, it may be startled. It may react as if being attacked by a mouse, flip its tail, hiss very quietly and quickly, and perhaps even musk. Remember, even though the snake may flip around quickly, they do not strike as part of defense. There are several techniques to avoid this natural defensive reaction. 1) First touch the snake with a light steady pressure. Do not tap or grab initially. Let it feel your warmth and realize you are not a danger. 2) If possible, slide your fingers into the substrate and under the snake and pick it up from underneath. 3) Keep the snake at room temperature or slightly lower. 75-78 degrees is a good temperature. If too warm, it may by agitated, and will not be anxious to take advantage of your warm skin.
Rubber Boas will likely want to wrap around your hand or wrist and stay put and enjoy your warmth. Wrap them around your wrist and wear it like a bracelet, or even as a necklace around your neck. Once the snake warms up, it may stay put not wanting to move, or more likely it will seek to crawl around looking for a place to hide. Support its weight and let it crawl from hand to hand.
Visit the Shedding Page for info about shedding.
© 2001 by Ryan Hoyer.