species very attractive for home keepers. They are fairly large bees, up to 11 mm (7/16") in length, and as a result have better body heat control, allowing them to live in regions where temperatures can drop a little lower than 0 °C (32 °F). However, they are somewhat selective about which flowers they will visit, preferring the flora that occurs in their natural environment. They are thus difficult to keep outside their region of origin, along the east coast of Brazil from the state of Bahia south. Other species, like the tiúba and the true uruçu, are also very tame and highly productive. Their colonies have from 3000–5000 individuals (for comparison, the population of honeybee swarms can peak at 80000 individuals) and can produce up to 10 liters (2.6 US gallons) of honey a year. They can be easily kept at home but will survive only in regions with a warm climate, their larvae dying at temperatures lower than 12 °C (54 °F). The yellow uruçu, however, can survive at temperatures lower than 0 °C (32 °F), and their colonies, bearing about 3500 individuals, can produce up to 6 liters (1.5 US gallons) of honey a year. But this species will react with powerful nipping if its nests are molested, and usually they are only kept by professional meliponicultors. Another suitable species for keeping at home is the guaraipo (Melipona bicolor). It is also quite tame, never attacking the beekeeper, and their colonies have fewer than 600 individuals. They can withstand temperatures as low as −10 °C (14 °F), and each colony can produce over 3 liters ( US gallons) of honey a year. Their colonies usually have more than one single queen at a time (usually two or three, but sometimes up to five), a phenomenon called polygyne, and thus are less sensitive to the death of one queen, which can cause the loss of a whole colony in other species. But the guaraipo is very sensitive to low levels of humidity, and their hives must be equipped with means to keep a high moisture content. Once very common, the guaraipo is now rather rare in nature, mainly due to the destruction of their native forests in the south-southeast of Brazil. Other groups of Brazilian stingless bees, genera Plebeia and Leurotrigona, are also very tame and much smaller, with one of them (Plebeia minima) reaching no more than