And immediately after Mic's fix:
Thigs were still loading at this point. What Mic recommended is that I use a random number to determine when a particular critter is going to die so that when I issue the command to die the critters don't all die at once.
In SL this bit of code gives a quite realistic movement for my critters:
vector newpos = newcoodinates(llGetPos() ,3.0);
But in OpenSim the critters don't seem to turn toward the target in response to llLookAt as they do in SL.