I have to give a class in two weeks on emplacing early warning devices
for a Forward Support Battalion's Brigade Support Area.  I have
located a number of resources through google on early warning devices,
but still do not feel confidant giving an hour and a half worth of jaw
on a subject I have no experience with.  What are some ideas for field
expedient early warning devices?  What are the most important things
to consider?  What are some activities I might involve my students
with to help them better understand how to create and emplace early
warning devices?