Cockroaches are included in the class Insecta under the phylum Arthropoda. Cockroaches are invertebrates which lack endoskeleton. Rather, they have an exoskeleton made out of chitin covering the entire body. They have a segmented body divided into 3 sections: head, thorax and abdomen. Head is made up of six fused segments showing mobility at its neck. The mouth section of cockroach has 4 parts: labrum, labium, pair of mandibles and maxillae.