Tyrannosaurus Pets

Rainbow Boa Care Sheet

Epicrates cenchria spp.

Rainbow boas are small to medium sized snakes from South America.  Under natural sunlight they shine with an iridescence that gives them their name.  Their small size and generally peaceful nature make them an excellent choice for a first tropical snake.  The three most commonly available species are the Brazilian rainbow boa (Epicrates cenchria cenchria), the Columbian rainbow boa (E.c.maurus), and the Argentine rainbow boa (E.c.alvarezi).  The smallest of these is the Argentine rainbow boa which is a slender snake reaching an adult size of 3.5’ – 4.5’.  Both the Columbian and Brazilian species are stocky snakes which can reach lengths of excess of 5.5’ though smaller is more common.


Because these are tropical snakes, they need a high night time temperature in order to thrive.  This is easiest to achieve in a wooden vivarium.  Glass tanks are poorly insulated, and often have large quantities of ventilation so keeping the temperatures high especially at night can be a challenge.  

A vivarium of 36” x 18” x 18” is big enough for an adult rainbow boa.  If you wish to use a larger tank then either 36” x 24” x 24”, or 48” x 18” x 18” is suitable especially for a female Brazilian rainbow.


The easiest way to heat your tank is to use a ceramic heating system.  These emit no light so can heat the tank at night without disturbing the snake.  Although initially more expensive than other heating systems they are also generally a lot longer lasting and more efficient than an incandescent lamp so should save you money in the long term.  Any heating system must be attached to a thermostat to control the temperature, and monitored using a thermometer.

Most rainbow boas require a basking spot of 32 – 34’c, ambient air temperatures through the middle of the tank should be 29’c – 32’c, with a cool end dropping to 26’c.  At night the tank should be maintained between 26’c – 28’c.

Setting up a ceramic heater

As ceramic heaters can get significantly hotter than incandescent bulbs you need to use a special heat resistant fitting to hold the lamp.  The fitting should be mounted about 8 – 10” in from one end of the tank, and in the middle of the tank from front to back.  The safest fittings to use are the porcelain hanging pendant style units. These are wired the same as a normal pendant fitting, but use heat resistant cable as it will last a lot longer.  The fitting needs to be hung from a hook in the roof of the tank.  Other fittings are available and one we have used with success for smaller ceramics (less than 100w) is a 200w rated batten style ES fitting.  Again this wires the same as a standard batten fitting but use heat resistant cable.  You can now screw the bulb into the fitting.  Always use a bulb guard to prevent your snake from burning itself.  These are simply screwed to the roof of the tank around the bulb.

Calibrating your thermostat

Drill a hole in the top back corner of the warm end (where the heater is) of the vivarium.  Feed the probe or sensor of the thermostat through this hole and leave it dangling to about 3” off of the floor of the tank.  If you make the hole at the bottom of the tank there is a chance that the snake will push it back out.  If you want to make the tank look neater you can house the probe cable in some conduit. If you do this make sure that the measuring part of the sensor (usually the bulbous part at the end of the cable) is exposed to the air of the tank.  Plug the heater into the thermostat, and plug the thermostat into the mains.  The thermostat is now controlling the heater.  Set the thermostat to 29’c.  The thermostat will now allow the ceramic to heat the point in the tank where the sensor is to 29’c.  Leave the tank running for at least an hour.  This gives everything thing to warm up and settle down.  Check the basking temperature, and the cool end temperature.  If these are correct leave the tank for another hour and recheck.  If the temperatures are still correct then the tank is now set up.  If at any check point the temperatures are not quite right adjust the thermostat slightly and try again.  Always leave the tank for at least an hour after an adjustment before checking the temperatures.  Once you have the tank stable at the correct level for two consecutive checks the tank is set up and ready for use.

Night time temperature

The rainbow boas need a night time temperature maintained between 26’c and 28’c. The easiest thing to do if you are simply keeping the snake as a pet is to leave the thermostat set for the day time temperatures.  The natural drop in your house temperature will drop the cool end enough for the snake to know that it is night.  If you are trying to breed your snakes then you will need to more accurately control the temperature and length of the night.  A range of equipment is available to do this please ask us for more details.

Checking the temperatures.

You should recheck all the temperatures at least once per week to make sure that everything is still running as it should be.  Also check the temperatures if there is a major change in the weather as either a hot spell or cold snap can affect the tank set up slightly.


The rainbow boas are for the most part tropical snakes and require a moderate to high humidity in the tank.  Using a bark mulch such as orchid bark or cypress mulch helps to raise the humidity.  The advantage of these substrates over other types such as beech chipping or aspen is that the mulch can be sprayed and won’t rot. The dry type substrates will quickly rot, or grow mould when damp however orchid bark absorbs the water and then slowly dries out increasing the ambient humidity as it does so.  Spray the tank a couple of times per week to achieve the desired humidity. If the snake is in shed it is useful to spray the tank more frequently.


Rainbow boas are not normally problem feeders and will take a variety of appropriate sized frozen thawed rats or mice.  Always defrost the food naturally to room temperature.  Do not thaw the food in hot or cold water or with a micro wave. Simply wrap it in newspaper or kitchen towel and leave on one side. The food will take between one hour and a couple of hours to defrost fully.  As most rainbow boas are nocturnal you will get a better feeding response if you offer the food in the late evening.  Always use tongs as an accidental bite from a larger rainbow boa can be quite painful.  A baby rainbow boa will eat either fuzzy mice, or rat pups.  As the snake grows move it onto a larger meal.  Young rainbow boas (up to about eighteen months of age) should be fed once every seven days.  Older snakes need food less frequently, and adults can be fed once every two to three weeks.  The difference in size between each type of food can be quite large.  In order to move the snake onto larger prey items we offer it multiples of the smaller food first.  A snake that is comfortably taking a rat pup can be offered two pups at the same time, when it is comfortable with two move it onto three.  Once it is taking three easily you can move up to the next size.  As an adult the snake will end up on a weaner rat (Argentine rainbow) or a small to medium rat (Columbian and Brazilian rainbows).

Cleaning the tank

The snake needs to have fresh water every day.  When you change the water bowl look around the tank for any obvious mess.  If you spot clean the tank regularly you will only need to do a full clean out once every four or five weeks.  When you clean out the tank put the animal somewhere safe and secure.  Remove the water bowl and any other décor.  Scoop out the old substrate.  Clean the tank with a damp cloth, dry the tank and put in fresh substrate.  Clean the décor and return this to the tank.  The snake can then go back.  Do not use household detergents or disinfectants.  Some of these can be highly toxic to reptiles.  If you feel that the tank needs a proper clean then any good pet store should have a range of reptile safe cleaners.

Handling your snake

When you first get your snake home, leave it completely alone until the animal has fed for you twice.  Spot clean and change the water every day, but don’t keep moving the hides or disturbing the snake, after seven days offer the snake food for the first time.  Leave the animal alone just spot cleaning and changing water for another week and then feed it again.  If the snake eats both these meals it has settled into its new environment and you can start to handle it.

You should always leave your snake alone for 48 hours after it has eaten.  Snakes eat a large meal in proportion to their body size, and excessive movement too soon after eating can cause them to regurgitate the food.  Snakes respond well to firm confidant handling.  Lift the animal from the mid point of its body with one hand.  As the animal comes off of the floor slide your other hand underneath to support the rest of the body.  Don’t allow the snake to wrap around your neck.  A rainbow boa is not going to get large enough to cause a problem, but it is good practice to always keep control of the animal.  Simply allow the snake to glide through your fingers. You shouldn’t have to hold the snake rather let the snake will hold you.  If a young snake is getting restless gently close your finger and thumb or two fingers together. Placing a small amount of pressure should slow the snake down and make it feel more secure.  Do not try to fully restrain the snake as this will cause it to panic.
Take more care if you are approaching an animal whose temperament is unknown, or one which is known to be aggressive. 

The different species of Rainbow Boa

Brazilian Rainbow Boa (Epicrates c. cenchria)

Peruvian Rainbow Boa(E.c.gaigei)

Espirito Santo Rainbow Boa(E.c.hygrophilus)

Marajo Rainbow Boa(E.c.barbouri)

Paraguay Rainbow Boa(E.c.crassus)

Caatinga Rainbow Boa(E.c.assisi)

Argentinean Rainbow Boa(E.c.alvarezi)

Minas Gerais Rainbow Boa(E.c.polylepis)

Venezuela Rainbow Boa(E.m.maurus)

Columbian Rainbow Boa(E.m.colombianus)

Guyana Rainbow Boa(E.m.guyanensis)

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Tyrannosaurus Pets