Spider hole
A spider hole is a type of defensive fighting position, similar to a surveillance/hidesite used for observation. Spider holes are designed to camouflage people (usually soldiers) into their surrounding environment.
The position was used additionally by Viet Cong fighters during the Vietnam War, the concept grew in popularity through the war. The Viet Cong occupied the spider holes temporarily, often leaving them after a few days.
The term was also used in 2003 during the capture of Iraqi president, Saddam Hussein, to describe his hiding position.