[Waterman]

It depends whether you are under rock or dirt. AND it depends on how important you are and whether they have the expensive stuff operating that can find you.

Wearing material like a survival blanket is better than going underground unless it is just really convenient. Remember that there is available material that is like a faraday cage it stops frequencies. It is about $35 per yard and for about $1000 you can canopy your bed and then add a space/survival blanket and you are pretty much gone!