Foraging Regulation
Collective decisions through encounter rates
The Foraging Problem
How does a colony decide how many foragers to send out? Too few and the colony starves. Too many and resources are wasted on unnecessary trips.
Gordon discovered that colonies solve this without any computation - they use return rates.
Return Rate Signals
The rate of successful forager returns determines the rate of new departures. If foragers return quickly with food, more foragers leave. If returns slow, departures slow.
No ant counts. No ant calculates. The physics of encounter rates does the optimization.
Absence of signal is itself a signal.
Self-Regulation
This creates automatic self-regulation. When food is abundant, fast returns trigger more foraging. When food is scarce, slow returns reduce foraging automatically.
The colony performs optimization without optimization algorithms.
Key Concepts
"The regulation of foraging depends on the rate at which foragers return, not on any assessment of the colony's needs."
Summary
The rate of successful forager returns determines the rate of new departures - no computation needed. The colony performs optimization without optimization algorithms by letting physics and chemistry do the work. Absence of signal is itself a signal.
Lessons from Ants at Work