What is Hive-Mind?
The collective mental activity expressed in the complex, coordinated behavior of a colony of beings or organisms regarded as comparable to a single mind controlling the behavior of an individual organism.
Hive-Mind allows a group of organisms to "share" the same mind. In some cases one individual could take control of another separate body to add to the hive. Each organism can work autonomously, though they think the same thing at the same time.
Shared intelligence. Collective consciousness or collective intelligence.