Originally designed by the Khalai caste to lay the foundation for protoss settlements, probes are robotic drones that service the Nexus and gather the numerous resources needed to power protoss technologies. Probes also manufacture and plant the micro-beacons that anchor the teleport matrices of structures. These beacons allow the protoss to warp-in prefabricated structures from their homeworld. Often probes are used as rudimentary spies, sent ahead to survey the potential locations of enemy encampments.