parasite... works wonders
i played yesterday and was a skulk hiding in a dark spot on the ceiling in (cant remember map, its the one with 2 big lockdown doors right outside the marine base).
There was a resource point below me, and some marines came out to get it. I waited a sec, and all but 1 marine left. The last marine started building a resource tower, and i tagged him with parasite from my hiding spot.
He spun around, and looked all over, but didnt see me, and went back to building. I let him have another parasite, and he looked around again, this time going all over the room. He went back to building, and i shot him again.
This time i could tell he was getting paranoid. He ran around the room, shooting everywhere. After about 10 sec, he went back to building. I shot him again, and he just freaked out, firing everywhere and jumping and using the radio comm.
A sec later he went back to building, but looked around occasionally. I tagged him again and just dropped on his head, biting it off. He died, and i took out the resource tower.
That was one classic moment. I suggest other skulks do this too.