Stay on the roofs, or on boulders, then call Burt Gummer http://images.wikia.com/tremors/images/8/83/Burtgummer2.jpg
I think he might be my next New Vegas character.
*snif* Tremors.... Me <3 Tremors..
On Topic:
I hate tunnelers both as concept and as creatures..
But on this subject I'll play along:
As long as they are out in the open no faction in Vegas should have problems with them, and as far as we know they only became a problem after the courier delivered his/her package... In other words if they would spread out from the divide (which I doubt, but Gingy and others would probably like me to stay out of that discussion) ... I think they will disturb the eco-system ... especially nightstalkers and deathclaws... and scavengers..
The city of Vegas itself as well as the direct surroundings has lights + noise, so everything needed to keep the tunnelers away..
A town like goodsprings would be risky, it is surrounded by caves.. and doesn't have trem...eh tunneler proof housing..