Boas are a nonvenomous snakes that constrict pray instead. They tend to be larger bodied snakes, and have 5 different subfamilies, ranging from the more common Boas Constrictors, through the beautiful Rainbow Boas, and the more unusual old world Sand Boas and Rosy Boas. Some Boas, such as the Common Boa, or Red-Tail Boa, can be quite big, with some locales known to reach up to 10-13ft in some cases, though 6 - 10ft tends to be more common. Small Sand Boas tend to only reach about 2ft on average though. As with many reptiles in the pet trade, there are variations, known as locales, available which vary in colour and pattern.