Wait, what? How do you know they have these energy shields and ray guns? You seem privy to knowledge about these first time invaders.... You're freaking one of them!!!
After considering Didge's answer, two different approaches come to mind: If these are extraterrestrials, I'd invite them in for a round of earth libations (assuming they didn't attempt to disintegrate us) and we would discuss comparative culture and human inadequacy, and fire up the grill.
If it were the earthbound type of aliens, I'd simply open fire.
This post was edited by Benedict Arnold at March 11, 2017 7:33 AM MST