DARPA SubT developed tunnel warfare technologies to rapidly map, navigate, and search underground tunnels employed for missile and nuclear arsenal

In recent years, underground settings are becoming increasingly relevant to global security and safety. Factors such as rising populations and urbanization are requiring military and civilian first responders to perform their duties in below-ground conditions, in human-made tunnels, underground urban spaces, and natural cave networks. Military and Security forces also have interest in developing robots to target  tunnels dug by Militaries and terrorists . Criminals, terrorists and military have been using  tunnels since long time to evade detection as surface based detection methods are ineffective underground .The tunnel threat is also a serious and growing concern to U.S and Mexico, as they enable human trafficking and smuggling of drugs and weapons across the border.