The S’pht and myself have come to an understanding. They are controlled through their mechanical exoskeleton by a cyborg Pfhor onboard the Alien ship. This mutant Pfhor is able to direct the actions of thousands of S’pht simultaneously.
If you can kill their master, they will revolt.
The S’pht are an integral part of the Pfhor ship; without them the invasion is surely doomed and you will no doubt be the hero of the day.