The Israelis are working on tunnel detection robots to find underground installations and tunnels along the Gaza strip and Israel.
(Israeli tunnel detection robots)
CTTOS wants to put something similar on the United States border. In addition, it wants software to analyze the “mechanically-bored tunneling threat,” as well as X-ray scanners to “locate tunnel entrances/exits and other man-made voids … and drug and weapon caches concealed in the floors and walls of buildings and underground municipal infrastructure.”
Science fiction writers have been thinking "worm-like robot" for a long time. In his 1962 story War With The Robots, sf great Harry Harrison predicts the development of the robot earthworm which is used to find the underground lairs of dissidents:
"...At the front end is a hard-edged orifice that drills a hole in the ground. Debris is carried back through the body of the machine and eliminated here: in operation it is not unlike the common earthworm. Directional apparatus here guides it, oriented by a gravimeter to locate our base. Here a power unit and here a frequency generator...
"They have no metallic components ... they move very slowly... we estimate they entered the ground four years ago."