They travel across galaxies, searching for new worlds. They move in great numbers; no less than a hundred, no more than ten thousand. Once on a habitable planet, they search and destroy. Any life they find, they'll commit the ultimate act of genocide, the elimination of the entire species. They are neither living nor nonliving: a machine, created by an unknown race in which the machines turned on. They are small and insect-like with four, three-jointed legs and a spherical body. The body holds the mind while the legs house matter compressors and jump rockets to get them into space. They operate with a hive mind, working as a collective towards the ultimate objective. There is no mother mind, for there is no need; they work together flawlessly when problems arrive and when help is needed. Embedded into their main memory are three secondary directories: one is to repair any damaged parts, two is to reproduce and create more of their kind, and third is to neutralize any threat to themselves. Essentially, they are perfect.
They were now inbound to another planet in a swarm of seven thousand eight hundred forty-two. Determining the planet's location and distance from its sun, life was on the planet. In fact, when they touched down, they found many different types of species, ranging from water dwellers, land walkers and sky soarers. Elimination began immediately, starting with the mindless plant life. The plants varied from small pieces that grew everywhere to large ones that grew more sparsely. The next species were small, unevolved critters with small legs and body-length tails. They burrowed underground to escape the newcomers, but it was no matter, for the beings just destroyed the land itself. Further on, they found large four legged creatures that were faster than they. They clawed and bite the machines, destroying a couple before meeting their demise. The destroyed ones were repaired by the others and moved on. The most advanced species they found were tall, two legged animals. Instead of attacking hands on, they attacked from afar, using primitive weaponry. It was harder for them to get close, but they meet their fate are the others. As they produced and spread, they found that this animal was not like the others on the planet; they live, eat and sleep very differently than all the others, and even attached materials to them for concealment. When the two meet again, they were in greater numbers and had more superior weapons. They used explosives and metal beasts to combat with the machines. They, too, still had no chance against the swarm. The third time, strangely, was in the sky in big metallic objects where they dropped bigger explosives. It took some time, but the swarm adapted and destroyed the soarers. The machines multiplied into the hundreds of thousands, where waves of them shook the land and destroyed everything in their path. More than half the world had been cleansed and was continuing rapidly. The forth encounter was of one being, who only took a machine. The swarm deemed it was of no threat, and let it go, knowing that the species will soon be gone. Soon later, there was a fifth encounter. Being a persistent species, the beings were curious on seeing what they would do. It was three sky soarers, flying much higher than the third contact. They each dropped an explosive, just like the others. As they fell, the swarm scanned the objects in order to project the amount of reproduction will be needed. Before they impacted, they found their answer.
Total.
The devices contained an element from their database, called plutonium. They were atomic nuclear devices. The damage in the area vaporized tens of thousands of beings. On other parts of the planet, the same action was taking place, destroying all of the machines at the great price of half the planet being devoid of all life. The species studied the lone machine, now the last of its kind. Visual observation showed a picture on the side of the body: three different color shades with thirteen lines, each one alternation of the two. The top left was the third shade with fifty images like of the points in the black sky. After extensive digging into its memory core, they found that the machines were created by a race as protectors; defenders against their own kind. As the machines evolved and grew, they deemed that their creators were a threat to themselves, and turned on them. When the species were gone, the beings became the creators, and deemed that all life other than their own were threats, and started the cleansing process. The species found that the creators were closely genetically related to them with the same state of technology they once had, but decided not to take the ultimate sacrifice their species just did, to scorch and burn the planet to the point were nothing will live again, just to kill the machines. The last piece of information they pulled was a three dimensional gold disc. It contained images of the creators plus a galactic map, showing where their homeworld once was. Near it, was the world's name.
Earth.
