The Dictyoptera are one of the Orthopteroid orders and are thus closely related to the Orthoptera (Crickets and Grasshoppers) themselves, as well as to the Phasmida (Stick-Insects), the Isoptera (Termites), the Grylloblattodea and perhaps more distantly to the Dermaptera (Earwigs). Both of the subgroups of the Dictyoptera i.e. the Cockroaches and the Praying Mantids are among those insect groups commonly kept as pets by many people throughtout the world. See the Blattodea Culture Group, and the Mantis Study Group.
They are described as variably sized insects with generally filiform (long and thin) antennae usually composed of many small segments. They have mandibulate or biting mouthparts and legs that are roughly similar (except the Mantids which have raptorial forelegs), most have 5 tarsi. Many species are winged and the forewings are generally hardened into a tegmina while the hind wings are often fan-like, the wing buds of the nymphs do not undergo reversal (i.e. the hind wings are not folded back over the forewings). The genitalia of both sexes are generally concealed, behind the 7th abdominal segment in the female and behind the 9th in the male. Cerci are present and males bear a pair of styles as well. No specialised stridulatory organs are present though some Mantids do have a single ear on the metathorax which allows them to hear the sonar of bats. The eggs are laid in an ootheca.
The order Dictyoptera is divided into two suborders (though in some taxonomic schemes you may find the two suborders treated as two independant orders), the Blattaria or Blattodea (Cockroaches) and the Mantodea (Mantids) commonly called Praying Mantids from the way they hold their raptorial forelegs. Here each group is dealt with separately.