Substrat: Ant colony behaviour arises from dynamical networks of interaction.
use local information; don't tell each other what to do; nobody understands needs on macro level
living systems cause own development
information = event that produces change of state
ants not individuals in ecological sense (individual ant doesn't reproduce); instead, colonies make more colonies; ant population is all nearby colonies
abuse from others: spiders mimic cuticular hydrocarbon profile to enter nest & eat larvae; spore-producing fungus infects/kills ants; queens inflitrate/take over nest
in complex adaptive systems local interactions determine global outcomes
patterns of interactions more important than content
enough ants must perform well often enough (perfection not necessary)
repeated behaviour is quasi-long-term memory (e.g. colonies "remember" trails for decades)
ants with outsized interaction rate have outsized impact on colony behaviour
ants regulate interaction rate (e.g. large colonies have idle ants which might buffer)
intuitive rule for ant behaviour: "if I meet ant with odor A ~3 times in next ~30 sec., probability I forage +10%, else -20%."
smaller groups use straighter paths (algorithm: when ant meets another, more likely to turn randomly)
colony growth
foundation: mating flight (reproductives from nearby colonies meet to mate), mated queen starts nest, lays eggs; initially, queen feeds/cares for brood
eggs grow into larvae and then pupae (inside the nest); ant emerges from pupal case & doesn't grow further; colony directs most food to feed larvae
colony growth has sigmoid shape (initial growth feeds growth because more workers)
high initial death rate; harvester ants: if 10 k ants & 2y colony, likely survives >20 ys
foragers don't scale linearly (harvester ants: 50% (20%) in 1 k (10 k) colony);
instead, more idle ants over time (excess capacity; maybe buffer for interactions)
colony mature when it begins to produce winged reproductives
older colonies use patrollers to avoid other colonies;
younger colonies return to foraging place even when there is colony overlap (maybe due to growth curve)