A good article on The Economist looks at simulating crowds here. It discusses how computational models of crowds is starting to enable more realistic behavior of humans. As an example, the article discusses the behavior of people during a fire blaze.
"The trouble is that the software that is used to do this generally treats people like particles in a fluid, says Mr Wittasek. “It assumes people behave like water flowing through a pipe,” he says. “They move at constant flow rates, heading for the nearest exits. But that’s not realistic.” Human behaviour is in fact far more complex and often quite irrational. When fleeing a fire people will often try to retrace their steps and leave the building by the way they came in, rather than heading for the nearest exit—even if it is much closer."
The article discusses the learning from the film "The Lord of the Rings" - where massive crowds of waring orcs were simulated with each individual orc having an independent brain to make decisions from a predefined set.
Of course, the article has a section labeled "The wisdom of the crowds"! Interestingly the article talks about crowds of humans and animals with examples.