Prey are caught and held securely with grasping , spiked forelegs ( `` raptoria ) legs '' ) ; the first thoracic segment , the prothorax , is commonly elongated and flexibly articulated , allowing for greater range of movement of the front limbs while the remainder of the body remains more or less immobile . Mantises have two grasping , spiked forelegs ( `` raptorial legs '' ) in which prey items are caught and held securely . The first thoracic segment , the prothorax , is commonly elongated and flexibly articulated , allowing for greater range of movement of the front limbs , while the remainder of the body remains more or less immobile .