Megapodes do not incubate their eggs with their body heat as other birds do, but bury them. They are best known for building massive nest-mounds of decaying vegetation, which the male attends, adding or removing litter to regulate the internal heat while the eggs hatch. However, some bury their eggs in other ways: there are burrow-nesters which use geothermal heat, and others which simply rely on the heat of the sun warming sand. Some species vary their incubation strategy depending the local environment or the season. Although the Australian Brush-turkey is the only species of bird in which sex ratio is confirmed to be incubation-temperature dependent, it is speculated that this is common to all Megapodes, as they share nesting methods unique among birds. The non-social nature of their incubation raises questions as to how the hatchlings come to recognise other members of their species, which is due to imprinting in other members of the order Galliformes. Recent research suggests that there is an instinctive visual recognition of specific movement patterns made by the individual species of megapode.
Many are shy, solitary, and inconspicuous, others live in colonies of many thousands of birds.
Megapode chicks do not have an egg tooth: they use their powerful claws to break out of the egg, and then tunnel their way up to the surface of the mound, lying on their backs and scratching at the sand and vegetable matter. Similar to other precocious birds, they hatch fully feathered and active, already able to fly and live independently from their parents.
Megapodes are found in the broader Australasian region, including islands in the western Pacific, Australia, New Guinea, and the islands of Indonesia east of the Wallace Line, but also the Andaman and Nicobar Islands in the Bay of Bengal.
There are 21 species in 6 genera. Although the evolutionary relationships between the Megapodiidae are especially uncertain, the morphological groups are clear: