Some spiders in this obscure family build short tubes on trees, usually in rainforest, while others construct them near or against trees at ground level. They are relatively small compared to other mygalomorphs, 5 to 10 mm in body length. In Australia there are four genera: Migas, Heteromigas, Bertmainius and Moggridgea. They are found in coastal rainforest in the eastern states including Tasmania, often in tree ferns. Pockets of suitable habitat in South Australia and south-west Western Australia support small populations. If one were lucky enough to see a migid, whose tubes are very well concealed by the trapdoor, it would be small and not very hairy, with widely spaced eyes, the eye region about three times wider than deep. While not very hairy, the legs can have spines. The spinnerets are quite short and the burrow usually has a door. World-wide they are found in southern Australia, New Caledonia, New Zealand, South America, Africa and Madagascar, usually in cooler mountainous rainforests. No bites have been recorded.