Well, I did something like this to kill them at the end of game:
Stealth-move behind them, Place C4, JAW to kill one in the middle, cloak, wait till everyone come to check the zone, uncloak, detonate C4, cloak, run away, get something heavy, like a Marshal, uncloak to lure them, cloak, move away, wait till they come in, shoot in the back to finish the game. Easy, and much more fun than melee.
Other way is - go cloaked into container, (right from entry point), get ammo from there, snipe one of these guys, hide behind the door, wait a moment, armor on and blind-shoot with K-volt till you find one - shoot till end of ammo, hide behind the doors, eventually all of aliens will stop at doors and you'll be able to Volt-them-all. very easily.
And yea, the C4 is best for pingers, otherwise they turn to be annoying.