The defensive behaviour of 18 species of mantids is described and further details are given of the defences of 12 species whose behaviour was described in an earlier paper. As a result the defences of 37 genera of Ghanaian mantids are now known. Most species of Mantinae have a general resemblance to their background and inSphodromantis lineolaandMiomantis paykulliithere is a correlation between colour of background and colour of insect. Most other species of mantid have a highly specific resemblance to bark, grass, sticks or leaves, and the evolution of these insects is discussed. Fire melanism occurs inGalepsus toganusandPyrgomantis pallida.Evidence is presented which suggests that the selective factor leading to reduction of wings in females of many species is predation by birds. Ten species of mantid have first instars which mimic ants, and inS. lineolafirst instars are positively associated withOecophylla,the ant they most closely resemble.Tarachodes afzeliinot only has nymphs which resemble ants but it preys extensively on ants as well. The functions of startle displays and the evolution of ocelli in mantids are discussed, and four types of territorial display which result in spacing out of nymphs are described.SUMMARYThe defensive behaviour of 18 species of mantids is described in this paper and further details are given of the defences of 12 species whose behaviour was described earlier (Edmunds, 1972). As a result the defences of 37 genera of Ghanaian mantids are now known. Most species of the Mantinae lack a specific resemblance to particular objects but have a green/brown polymorphism, and evidence is presented showing that there is a correlation between background colour and colour of the mantid inSphodromantis lineolaandMiomantis paykullii.Most other species of mantid have a highly specific resemblance to bark, grass, sticks or leaves, and the evolution of these insects is discussed. Fire melanism occurs inGalepsus toganusandPyrgomantis pallida.Evidence is presented which suggests that wing reduction in females results in decreased predation by birds. Wing reduction gives better primary defence but the wings cannot be completely lost if they are also used for a startle display in secondary defence.Many species of mantid have first instars which mimic ants and the fact thatS. lineolafirst instars have a positive association with the antOecophyllaindicates that ant mimicry is of defensive importance. Species which have relatively unspecialized adults normally have ant‐mimicking nymphs (e.g. most of the Mantinae), but some species which have highly modified adults do not have ant‐mimicking nymphs, probably because already at the first instar the nymph is “preadapted” to becoming an adult and so cannot resemble an ant.Tarachodes afzeliinot only has ant‐mimicking nymphs but also lives amongst and feeds on ants. It has a special technique for knocking off ants which come near it and which it cannot eat.The functions of startle displays and the evolution of ocelli inPseudo‐creobotraare discussed.Territorial displays which result in spacing out of nymphs are described. These result in reduced cannibalism and they may also serve to partition out the available food resources. Not all mantids have territorial displays, but four different displays have evolved in different species which appear to have th