Insect morphology least three different positions: prognathous, opisthognathous, and hypognathous. In species with prognathous articulation, the head is positioned vertically aligned with the body, such as species of Formicidae; while in a hypognathous type, the head is aligned horizontally adjacent to the body. An opisthognathous head is positioned diagonally, such as species of Blattodea and some Coleoptera. The mouthparts vary greatly between insects of different orders, but the two main functional groups are mandibulate and haustellate. Haustellate mouthparts are used for sucking liquids and can be further classified by the presence of stylets, which include piercing-sucking, sponging, and siphoning. The stylets are
RID Insect Repellent against mosquitoes, biting flies, chiggers, fleas and ticks. These insect repellents slowly evaporate into the air, producing an invisible chemical barrier around the areas on the body and clothes where it is applied, repelling incoming insects.<ref name="Repellents/AMCA"></ref> RID was invented in 1956, after 3,000 hours of field research by inventor Doug H. Thorley. A bottle of RID is exhibited at the Queensland Museum in Australia. RID insect repellents are used to repel insects which may carry a number of diseases, including; Ross River Virus, Dengue Fever, West Nile Virus, Malaria, Yellow Fever, Japanese B Encephalitis, Filariasis, Lyme Disease, Leishmaniasis, Typhus