Summary: To destroy the human presence, the bacterium employs lifeforms of its own. These are the creatures that slaughter the crew of the ship or base, and the same creatures that are waiting for the Frontiersmen when they arrive to take the ship or base back. Kharaa species have natural weaponry and cunning that make them a match for the best equipped and most highly trained forces we can deploy. To read about these species, click here. Hives continue to spawn over the course of a conflict, replacing lost aliens. Destroying all hives is the only way to defeat the Kharaa.

The hives seem to act as living libraries – they contain information the bacteria uses to respond to threats to its control of an area. The first hive provides basic information – how to create Skulks, Gorges and Lerks. If the enemy presence is strong, a second hive, and even a third provide more and more information, allowing more complex species – the Fade and Onos. The Kharaa will tend to conserve resources by upgrading their response one step at a time, until the threat is destroyed.

Hives do more than contain this information, they act as the birthing zone for Skulks. It is unlikely Skulks have always birthed this way – it seems to be an example of highly specialized evolution. As the first step of response, Skulks are the most basic, resource-effective answer to the human presence. As more resources are made available, each Skulk can choose to gestate into a more complex species. The same individual Kharaa may gestate up through all five species over the course of a conflict.