The Brazilian Rainbow Boa (Epicrates cenchria chenchria) is just one of the 9 or 10 subspecies of rainbow boas, but it is the most common one found in the pet trade. It is a medium sized snake rarely getting longer than seven feet, more often being four or five feet long, and being slender in build The scales give an iridescent sparkle caused by tiny ridges on the scales. These ridges refract light like tiny prisms. Colors vary for the different subspecies, but the Brazilian is often orange with black rimmed circles along its back.
Rainbow boas are active snakes needing a roomy enclosure to move around in. A container such as a 40 to 50 gallon aquarium is considered a minimum space for a single rainbow. Try to provide four to six square feet of floor space for this snake, and give it branches for climbing. It will appreciate hide boxes, like all snakes. Of course the cage needs to close very securely, to guard against escape. Each rainbow boa should have its own enclosure unless it is breeding season.
Babies need to be kept in smaller containers, such as plastic shoe boxes with holes punched in the sides. The box should be lined in damp paper towels. It should be equipped with a hiding place and a water bowl. Hides for snakes can be as simple as an upside down plastic butter dish with an entry hole cut into the side. These shoe boxes can be used for the first month or two. Baby snakes are sometimes nervous and unable to find their food when their enclosure is too large.
The cage needs to have a substrate to line the bottom. Newspaper or paper towels are easy to replace when soiled. Cyprus mulch and orchid bark are other choices. Many owners use a piece of Astroturf or special reptile carpeting cut to the size of the cage. If you have two pieces, you can use one while washing the other. Cedar chips should never be used because the oil in them is toxic to snakes.
The rainbow boa needs a temperature gradient ranging from 75 for a nighttime low to 85 for a daytime high. A basking spot of 90 degrees is OK, but too much time at this high temperature is not good for the snake. If the snake tends to hang out at one end or the other of the enclosure, you can adjust the temperature a few degrees to suit it. For instance, if it huddles in the 85 degree end, you might want to raise the temperature a bit. If it clings to the window on the cool side, the high temperatures should go down a degree or two. Keep a thermometer on each end so that you can monitor the temperature.
There are several ways to heat the rainbow's enclosure so that it offers this heat gradient. One is to set the enclosure half on an under cage heating pad. These are available from pet stores. There is a product called a "hot rock" that is an electric heated fake rock. These are generally discouraged because they get too hot and burn snakes. Another good method is the use of a type of ceramic heat bulb that emits heat but not light. Similarly, some shake owners use light bulbs to add warmth, but these must be turned off at night. The easiest method is to use a light bulb on a timer to provide 12 hours of light and heat and then 12 hours of darkness in a cooler environment.
Rainbow boas also need a high level of humidity in their enclosure, and benefit from being misted several times a day. In addition, they should be given a large water bowl that is big enough for them to soak. Strive to keep a relative humidity level of 75 to 80 percent. This can be measured with a hygrometer. A solid lid with ventilation holes will help keep humidity in better than a screen top. If you must use screen, it can be partly covered with plastic wrap or Plexiglas to help keep in moisture.
A special method of providing extra humidity is to make a humidity box for the snake. Line a lidded plastic container with damp sphagnum moss, and give it an entry hole. The snake can enter this container when it feels a need for even more humidity. The sphagnum moss needs to be changed at least once weekly in order to keep the snake enclosure free of mold.
The cage needs to be cleaned frequently. Bedding should be changed at least every week. Because of the humidity, mold can grow in the cage if it is not kept clean. But without the humidity, snakes will regurgitate, and possibly even die.
Many other snakes tend to get blisters if they don't have a dry place to be from time to time, but the rainbow boa doesn't seem to have much of a problem with this. It is still beneficial to keep a dry area for them if desired.
Food for the rainbow boa is a pre-killed rat about every two weeks for adult rainbows, and every week or ten days for young snakes. The size of the food should be a little smaller than the widest diameter of the rainbow boa. It is always preferable to feed dead food over live food, even though many snakes resist eating dead food in the beginning. Live prey animals fight back, and can injure the snake. Some owners raise their own feeder mice and do the job themselves, while others buy the mice frozen. Rainbow boas are naturally slender. They often get obese in captivity, so be careful not to feed them too much.
If you're considering buying a Brazilian rainbow boa, be aware that the babies tend to be a bit nippy. However, they can usually be tamed with proper handling. A rainbow boa is probably not a good beginner snake as some people report the snakes have a tendency to bite. I personally have a Brazilian rainbow boa, and have never been bitten, and handle mine several times a week. A couple tips for handling a rainbow boa - make sure you're handling a captive bred snake, and always wash your hands before handling the snake especially if you've eaten meat recently.