The Formics are an advanced space-faring alien species. Although they are officially known as Formics, they are nicknamed Buggers by humans due to their insect-like appearance. This race of Ramen is made up of a Hive Queen and her subjects. They share a mind, so the loss of individual units does not concern them. They killed several humans in the belief they were simply stopping communications, which led to the Formic-Human war consisting of the First, Second, and Third Invasions.
They hacked the Mind Game in Battle School in an atttempt to communicate with Ender Wiggin. Although they failed to talk to him, the interaction led Ender to discover their queen on a planet they had inhabited. He was then able to to keep her with him on his voyages. She was able to reproduce on the pequenino (piggie) homeworld, Lusitania.
The Formics were an insectoid species, and were similar to earthly ants and bees in societal structure. The Hive Queens, who were the central minds that controlled the entire nest telepathically, were about three meters long. The workers were barely one meter in length.
The Hive Queen has a highly adaptive immune system, which worked effectively enough to keep them from medical research and kept them safe from the Descolada.
Main Article: Hive Queen
Hive Queens are the commanding intelligences behind a nest, and are capable of telepathic communication among the rest of the Hive Queens. The Hive Queen was the only one capable of laying eggs, after biting the head off a drone and fertilizing her eggs.
When a Hive Queen egg is laid, a worker has to be fed to the fertilized egg. The Hive Queen is given a philote only after its birth, and the mind of the entire population of Buggers is absorbed by the newborn queen.
A Worker is usually one meter in length, and are directly controlled by the Hive Queens. The worker does the construction, repair, and other efforts necessitated by keeping the nest healthy.
Originally, the Formic homeworld was divided between rival and constantly warring nests, each controlled by a single queen, fighting against all of the others without any alliances. Even a newly hatched queen would always fight its own mother to the death. Formic civilization truly began when one mother-queen managed to coax its daughter-queen into not fighting it, to put an end to the senseless slaughter and benefit from joining forces. Automatically, this made their faction stronger than all of the others, as no two queens had ever allied before. In turn, each of the new queen's daughter-queens convinced its own daughter-queens into working together, until after several generations the descendants of that first forward-thinking hive queen had eliminated all of the other nests and spread across their homeworld.
The Formics made a disastrous first contact with humanity in what would become known as the First Invasion. The Formics did not comprehend that any species could be truly sentient if it did not possess a hive-mind, assuming that a hive-mind was a prerequisite for sentience. The Formics established a forward base on the asteroid Eros and killed the human exploratory crew that came to investigate, thinking they were simply animals. The First Invasion was devastating and the human space fleet took massive losses. A single Formic ship managed to get through to Earth and killed millions of people in China.
The Formics responded with the Second Invasion, however, the ship containing the local hive queen was targeted and destroyed, sending the Formic fleet into complete disarray. From this clearly intelligent military action, the Formics realized that humanity was sentient, and became horrified at the millions of deaths they had caused. Therefore, the Formics decided not to send another invasion fleet.
Unfortunately, this realization came too late, as humanity had already begun to respond to the seemingly genocidal intentions of the Formics. As soon as seemingly miraculous defeat of the Formics in the Second Invasion was finished, every available ship was sent out in the International Fleet to attack Formic space, driving towards their homeworld. Due to relativistic effects, many years passed on Earth while the International Fleet traveled to the Bugger homeworld. Finally, they launched the "Third Invasion" -- an invasion of the Formics by humanity.
Ultimately, under the leadership of Andrew "Ender" Wiggin, the International Fleet defeated the Formic fleets, and arrived at the Bugger homeworld itself. In the final battle, Ender deployed the "Little Doctor" device against the planet itself, completely destroying it and the entire Formic race in what would become known as the First Xenocide.
However, forseeing this course of events, the Formics had hidden away a hive queen cocoon on a colony world they knew Ender would visit. The new hive queen communicated to Ender the history of her race, and their mistaken attack against Earth. Wiggin then set out on a relativistic journey to distant colony worlds looking for a suitable place for the hive queen to make a new nest. Three thousand years passed on Earth while Ender spent twenty relativistic years searching, until he arrived at Lusitania. There, the Hive Queen began a new Formic colony, resulting in the planet becoming home to three different species: the native Piggies, human colonists, and Formic colonists.