Hive mind

From Memory Alpha, the free Star Trek reference

A hive mind is the collective sharing of minds into a single consciousness, serving and driving the goals of its entire population. As such individuality in a hive mind is sacrificed for the whole, and its members/resources are assigned tasks according to how to best achieve those goals. Hive mind societies encountered by the Federation include:

• The Body of Landru (TOS: "The Return of the Archons")
• An species of neural parasite that infested Deneva in 2267 (TOS: "Operation -- Annihilate!")
• The androids of planet Mudd (TOS: "I, Mudd")
• The Borg Collective (TNG: "Q Who")
• The Borg Cooperative (VOY: "Unity")