can replace her. For Plebeia quadripunctata, although fewer than 1% of female worker cells produce dwarf queens, they comprise six of seven queen bees, and one of five proceed to head colonies of their own. They are reproductively active, but less fecund than large queens. Soldier caste While the existence of a soldier caste is well known in ants and termites, the phenomenon was unknown among bees until 2012, when some stingless bees were found to have a similar caste of defensive specialists that help guard the nest entrance against intruders; to date, at least 10 species have been documented to possess such "soldiers", including Tetragonisca angustula, T. fiebrigi, and Frieseomelitta longipes, with the guards not only larger, but also sometimes a different color from ordinary workers. Stingless bees of Australia Of the 1,600 species of wild bees native to Australia, about 14 are stingless. These species bear a variety of names, including Australian native honey bees, native bees, sugar-bag bees, and sweat bees (because they will land on a sweaty person to drink in dry times or areas). All are small and black in colour, with hairy extended hind legs for carrying nectar and pollen; because of the latter, they are sometimes mistaken for bumblebees. The various stingless species look quite similar, with the two most common species, Tetragonula carbonaria and Austroplebeia australis, displaying the greatest variation, as the latter is smaller and less active. Both of these inhabit the area around Brisbane. As stingless bees are harmless to humans, they have become an increasingly attractive addition to the suburban backyard. Most meliponine beekeepers do not keep the bees for honey, but rather for the pleasure of conserving a native species whose original habitat is declining due to human development. In return, the bees pollinate crops, garden flowers, and bushland during their search for nectar and pollen. While a number of beekeepers fill a small niche market for bush honey, native meliponines only produce small amounts and the structure of their hives makes the honey difficult to extract. Only in warm areas of Australia such as Queensland and northern New South Wales can the bees produce more honey than they need for their own survival. The bees only come out of the hive when it is above about 18 degrees Celsius (64 degrees Fahrenheit). Harvesting honey from a nest in a cooler area could weaken or even kill the