Mantids and cockroaches share the order Dictyoptera; and mantids within this the suborder mantodea.  Praying mantises are aggressive raptorial insects, lying camouflaged in wait for prey before striking out with lighting speed.  The prey is then held and eaten alive:

African Green Mantis (Sphodromantis lineola)
Mantid nymph (?sp)

Canon EOS 300D and MP-E 65mm, with multiple fill-in flash