Unfortunately, there have been a number of cases where large pythons have caused serious injury and even death to humans - some children and some adults. These have happened with very large constricting snakes, and are certainly isolated events. However, the risks are there, and proper education and precautions are necessary to prevent tragic incidents. A length of eight feet is often recognized as a safety threshold - any snake that reaches an adult length of more than eight feet requires a very secure enclosure and experts often recommended that two people be present to handle such large snakes. In fact, is is a good idea to have a person for for each 4 feet of snake; for example, 3 people to handle a 12 foot snake and 4 people for a 16 foot snake. Feeding is a vulnerable time for owners of large snakes and it is recommended that there at least be other people present when feeding to assist if necessary (most of these snakes only eat once every 10-14 days or less). Burmese pythons are generally gentle but are extremely large and powerful snakes, and have been involved in fatal incidents. Red tailed boas (commonly known as boa constrictors) are not as large but are still powerful and not recommended for beginners. Reticulated pythons grow very large and have a reputation for nasty temperaments, and if kept at all are only suitable for very experienced handlers. Recommended reading includes:
- AFH on Large Constrictors - guidelines published by the American Federation of Herpetoculturalists on the keeping of large constrictors.
- Handling Large Constrictors - by Lenny Flank, precautions to take when keeping large constricting snakes. Good advice.
There is a significant variation in the care and housing arrangements between the different species so readers should seek out specific care information for each species. All these snakes are carnivores, and most experts recommend that killed prey be fed. Not only is it easier on the owner but there is no risk of the snake being bitten or otherwise injured by the prey (a mouse or rat can inflict significant injury on a snake if given a chance).
Finally, an important disease of boids: inclusion body disease. This is a virus which is fatal in pythons and boas who exhibit symptoms. It is impossible to tell for certain if a snake has been exposed (and some snakes are asymptomatic carriers) and it can take months for signs to appear. Do not buy an apparently unhealthy snake, and if you have snakes at home already, quarantine new arrival for a minimum 3-6 months (and always be sure to wash hands between handling snakes). For more on the disease and it's prevention, I recommend reading this:
Some information on this viral disease that affects boas and pythons, Melissa Kaplan.