Starseed

Starseeds are an alien life form in the Known Space universe of Larry Niven's science fiction novels. There is not much information available on them, as they are quite difficult to understand. These "seeds" are about a mile wide in diameter, and they float through the galaxy. It is said that they come from the core of the galaxy and float to other planets near its rim, before ejecting their "eggs" and returning to the galaxy's core.

Starseeds and Known Space
It is revealed in Niven's novel Peace and Freedom that starseeds are actually ejecting microorganisms on these planets in order to create new life, hence the term "starseed". A super advanced alien race called the Outsiders track down starseeds because once a planet is seeded with life, new races are created and they in turn become customers of the Outsiders. However, it is unclear whether or not the Outsiders actually create the starseeds themselves.

The Pierson's puppeteers say that they have created a technology called a starseed lure. As made obvious by its name, it attracts starseeds towards a certain solar system or planet. It is said that they used a starseed lure to attract starseeds, and by extension, Outsiders, to a human colony. Since they manipulated many of the events in the history of the human race, it is a possibility that this could have been a large factor in the result of the man-Kzin war, since the technology needed by the humans to win that war was obtained from the Outsiders during that particular visit.