Brood X Insect is a term used to refer to the CICADA, a six-letter insect. Cicadas are a type of insect that can be found in many parts of the world. They are known for their loud and distinctive sound, which is produced by males as part of their mating call. They have a long life cycle, with some species taking up to 17 years to complete their life cycle. Brood X is a particular group of cicadas that emerge in large numbers every 17 years in the eastern United States.