here's what I have found to be useful:
1) stay out of corn fields at night
2) Don't live in the middle of nowhere...AKA B.F.E.
3) Join a group of ever vigilant sky watchers so you can be well informed.
4) don't shower for weeks pior to impending body snatching events.
5) tin foil
6) if all else fails, use a tazer gun! (STOP RESITING..**shock** STOP RESITING!!).