In a swarm of bees, each bee does a very simple action.

And yet the overall swarm has distinct, large scale, highly complex emergent behaviors.

Part of what allows this to happen is stigmergy.

The actions of bees accumulates real state in the physical world that other bees can respond to.

It could be as simple as one bee being in one location, making it impossible for another bee to be in that precise location at that time.

Or it could be accumulating state, e.g. building up beeswax in one part of the hive.

This shared state, with each bee modifying it just a little according to some simple program, can lead to amazing outcomes.

Not too dissimilar from the blackboard model of intelligence