These are the easiest to place...
Toss one of these suckers into a map, give it the initial command of
and it will be on you like a 17 year old on a Friday night. This works for Simple_runner, simple_drone and simple_facehugger.
The problem with these simple AI, is they can't be scripted. They are one notch above the Active Props we have studied earlier. They just follow a straight line from their position to the Player. They take up very little processing in game, cause they are not really thinking and have very few options.
the only other command they respond to:
msg simpleAI47 REMOVE
which will get rid of it from the map.
The MULTISPAWNER can make good use of these pesky AIs in some situations. For example remember when Harrison went into the small hive to save HALL and then all hell broke loose when he had to escape, that overwhelming barrage of alien AI was probably Simple, coninuously being spawned by an MULTISPAWNER.
(The AI in AvP2 is infinitely suprerior to the simplistic AI from the first game which was basically a SIMPLEAI) the problem came in how it was utilized, not in the coding.