Antlions live in underground colonies, typically situated in sandy areas such as beaches. They usually hide under the sand, waiting for anything to venture near, at which point they quickly surface and tear it apart. Their aggression is not limited to humans or the Combine, and they will attack other xenofauna such as headcrabs. Antlions sense a victim's presence via vibrations transmitted through loose soil or sand. This makes it possible to safely venture through Antlion territories by walking solely over foreign items placed on the sand, or by walking across rocks. Once on the surface, Antlions can fly short distances to rapidly approach their prey. The Combine refer to Antlions as "virals," "biotics," or "exogens", as a soldier can be heard mentioning a "full biotic overrun" of the Nov