Ten segments can be distinguished in the tapering abdomen, the ninth frequently bearing a pair of tail-feelers (cerci), and the tenth, attached ventrally to the ninth, having the anal opening at its extremity and performing the function of a posterior limb, supporting and temporarily fixing the tail end of the insect on the surface over which it crawls.
The carabid larva is an active well-armoured grub with the legs and cerci variable in length.
With very few exceptions, the larva in this group is active and campodeiform, with cerci and elongate legs as in the Adephaga, but the leg has only four segments and one claw.
In the more generalized insects the abdomen evidently consists of ten segments, the hindmost of which often carries a pair of tail-feelers, (cerci or cercopods) and a terminal anal segment.
In some cases, however, it can be shown that the cerci really belong to an eleventh abdominal segment which usually becomes fused with the tenth.