Australian bees are extremely diverse in terms of size, form, colouration, degree of sociality and behaviour and relatively few resemble the familiar honeybee. Our tiniest bees are only about 2.5 mm long while our largest are about ten times as long. Body form varies from broad and rotund to slender and delicate. Some bees are densely hairy while others are sparsely hairy or almost hairless and some are very wasp-like. Our bees are classified into five families, three of which are known as ‘short-tongued’ and two as ‘long-tongued’. The ‘tongue’ is a flexible hairy extension of the proboscis used for lapping up nectar and for applying secretions during nestbuilding.