Nomes are a species of aliens who were forced to land on the earth until they could summon their ship (The Starship Swan) and leave. At the time of the events in the Bromeliad the Nomes had reverted to barbarism and what technology they had access to was mainly borrowed from humans.
Nomes are about four inches tall with a lifespan of around ten years. As a result of this they live and move approximately 10 times as fast as humans. This is the main reason they have escaped detection by humans. Although there has been some contact it is mainly dismissed as fairy stories.
Nomes, before landing on earth, had reached a very high level of technology and had developed space travel and thus colonised space.
Main article The Thing
The Thing is a highly developed computer. While in the care of The Tribe it was dormant due to lack of power but once brought to electricity it was activated and then able to direct and assist the nomes to leave the planet.