▁insect ▁communities ▁of ▁the ▁Car bon ifer ous ▁period . ▁Modern ▁co ck ro aches ▁radi ated ▁from ▁them ▁by ▁the ▁middle ▁of ▁the ▁Mes oz o ic . ▁This ▁group ▁of ▁insect s ▁are ▁no ct urn al , ▁only ▁for aging ▁for ▁food ▁and ▁water ▁at ▁night . ▁They ▁are ▁not ▁considered ▁e uso cial ▁because ▁their ▁populations ▁are ▁not ▁divided ▁into ▁different ▁cas te ▁systems ; ▁however , ▁they ▁are ▁still ▁social ▁cre atures ▁and ▁can ▁live ▁in ▁groups ▁with ▁over ▁a ▁million ▁individuals . ▁The ▁co ck ro ach ▁is ▁fl atten ed ▁d ors ol ater ally ▁and ▁is ▁roughly ▁o val ▁with ▁a ▁shield - like ▁plate , ▁the ▁pron ot um , ▁covering ▁its ▁thor ax ▁and ▁posterior ▁region ▁of ▁the ▁head . ▁The ▁anten na e ▁are ▁many - segment ed , ▁long ▁and ▁sl ender , ▁and ▁the ▁mouth parts ▁are ▁adapted ▁for ▁che wing . ▁The ▁for ew ings ▁are ▁normally ▁le ath ery ▁and ▁the ▁h ind ▁wings ▁memb ran ous . ▁The ▁co x ae ▁of ▁the ▁legs ▁are ▁fl atten ed ▁to ▁enable ▁the ▁fem urs ▁to ▁fit ▁neat ly ▁against ▁them ▁when ▁fol ded . ▁C ock ro aches ▁are ▁hem imet abol ous ; ▁there ▁is ▁no ▁pup al ▁stage ▁and ▁the ▁n ym ph s ▁res emble ▁the ▁adult s ▁apart ▁from ▁their ▁size ▁and ▁the ▁absence ▁of ▁wings . ▁Fem ale ▁co ck ro aches ▁produce ▁an ▁egg ▁sac ▁known ▁as ▁an ▁o othe ca ▁and