Fireflies exhibit synchronus flashing where a population will flash in unison.
There are multiple approaches to the sync, from sutble adjustments to complete resets. The very simplified model involves having each node maintain an excitement level which builds over time, and once it reaches a given threshold causes the node to flash (and reset the level). If a node is nearby a neighbour that flashes, the flash causes the node to also fire (and reset the excitement level). This slowly moves the nodes closer together over time.
Original simplified model proposed by Richmond in 1930 (see "Fireflies flashing in unison" Science 71.1847 (1930): 537-538.)
Although there was a hint on this approach in 1915 (see Luminous Insects Nature 1915)
There were many incorrect theories involving random happenstance (gusts of wind) or leader-based protocols. These persisted until well into the 1930s (see Synchronus Rythmic Flashing of Fireflies Buck 1938).
While I believe this approach could work strictly with pheromones, I have only implement this using a k-nearest-neighbours / quadtree based approach to find the neighbours within a given range (therefore providing a more top-down approach than would be nice in the model).