A Bug hole is informal terminology used by most Mobile Infantrymen to refer to any cavernous opening created or occupied by Arachnids. Bug holes are often times entrances to elaborate tunnels and corridors occupied by a variety of Arachnid species. Bug holes are early warning signs of a bug presence and are often addressed by troopers using Nuclear weapons to destroy these access points. Sometimes troopers may explore bug holes to locate source targets to either capture or destroy. Bug holes are also means through which bug forces can infiltrate trooper bases as seen before the Battle of Whiskey Outpost, where the Roughnecks discovered the Outpost had been overrun after a bug hole was made just under the base's mess hall.
Bug holes can emerge almost anywhere at anytime. Sometimes bug holes may already exist under thin layers of a planet's surface. Many troopers have found themselves caught in instances when the ground beneath their feet collapsed and caved inward, revealing existing bug tunnels. Most bug holes are made by burrowing-type bug species. Varying story canons have featured species ranging from Tanker Worms, to Tanker Bugs. Regardless of the species digging tunnels, the objective remains the same: to facilitate the movement of large numbers of Arachnid forces beneath the surface of any planet in secret. Bug holes also facilitate breeding chambers for new generations of the bug species as observed in the Tesca Campaign in the Roughnecks: Starship Troopers Chronicles story canon, where the Roughnecks discovered mutated breeds of bugs being cultivated inside tunnels beneath the planet's surface. In the same canon, a bug hole emerged in the heart of a Tesca hospital base after a Tanker Worm had been tasked to burrow a tunnel for swarms of Control Bugs to storm through. In most instances, the bug hole is the Arachnids' most effective means of travel and infiltration in their ongoing fight with the human race.