Brazilian Rainbows can be bred at two and a half years of age if the females are large enough and have enough weight.  A female should be at least five feet and weigh over three pounds.  Another six inches of length and pound of weight is more appropriate and should produce a larger first litter with less strain on the snake.  Standard boid cooling seems to be necessary to allow the formation of egg and sperm cells.  Brazilian Rainbow Boas will usually begin breeding within a few weeks of being warmed back up after the cooling period.  Females will show a very marked mid body ovulatory lump for several hours.  This lump is usually not seen because it lasts for such a short time.  Most gravid females will refuse to feed.  They will sometimes take a very small prey animal while they are gravid.  Many females will become enormously large in the back half of their body and look very emaciated in the front half late in gestation.  Reproduction takes an extreme amount of energy and should only be attempted with very healthy adults.  Gestation lasts approximately five months.  The female will often appear restless and cruise around the cage as if looking for something for a day or two before laying.  Laying often occurs during weather changes.  Female snakes should NOT be disturbed while they are laying as this may cause them to interrupt oviposition which can lead to incidences of stillborn babies.  Females often eat recently laid infertile slugs.  I have never witnessed a female eating babies but recognize that the possibility exists for a snake which is picking through a pile of live babies and slugs to devour a newborn baby accidentally.  For this reason I try to remove the babies from the mother soon after they are born.  Many babies will strike at anything that moves.  They can be tamed fairly quickly by handling them gently and regularly over the first few weeks.  They will often eat before they have shed.  The first shed usually occurs after 10 to 14 days from birth.  Shedding should occur about once a month or slightly more often in heavily fed ones while they are growing and then occur about every other month.  I feed my yearling boa once every 4 or 5 days without any signs of becoming obese.  Later in life feeding too heavily can lead to an unhealthy overweight condition.  All healthy Brazilian Rainbow Boas seem to eat readily at all times except for when they are ready for breeding during cooler winter months.  Refusal to feed is almost always due to husbandry or health problems.  Health problems are often due to husbandry problems.