The simulation needs a Java-Plugin (1.3.x) installed for your internet browser. If you do not already have one installed, the browser will prompt you to
download the Plugin from “Sun”, who is the inventor of Java. Please download the JRE (=Java runtime environment) into a directory on your computer (e.g. “c:\temp”), execute the downloaded file for installation on
your system (double-click on the file). Afterwards you will be able to reload the simulation page. Maybe you will have to restart your browser to succeed.
Run the simulation
Please click here.
Description of the simulation
The simulation is based on the simulation “building performed by termites”.
We added an environmental template to the simulation. In a termite nest, the queen resides in a special chamber. The workers construct this chamber by
erecting walls in a certain distance around the queen. As the queen grows by time, they adapt the chamber permanently, so that it always perfectly fits to the queen.
A similar behavior can be found in several ant species, which place a wall of grains around their broodnest.
These processes are assumed to be self-organizational but influenced by an environmental template. The
termite queen and the brood of ants produce pheromones that spread through the surrounding air. This is a diffusion-like process. It establishes a gradient of pheromones around the queen (or the brood nest) that
provides additional cues for the workers whether they should erect piles or not. Only within a certain range of pheromone concentrations the workers erect piles that later build walls. A plot showing such locally
different building probabilities is shown here:
All pictures taken from: Bonabeau E., Dorigo M. and Theraulaz G. (1999) Swarm intelligence. From natural to artificial systems. Santa Fee
Institute studies in the sciences of complexity. Oxford University Press
The slider density-of-chips sets the density of chips distributed randomly at the beginning
The slider number sets the number of termites that are used in the simulation
The sliders Puturn and turn-angle set the basic parameters of the random walk. Please note that the ants always perform simply a random walk.
The slider queen-growth-rate determines the growing speed of the queen
The sliders evaporation-rate and diffusion-rate determine the physics of the queen pheromone in our simulation.
- Check how the number of actors and of the chip density affect the sorting speed and result.
- Check how the growing rate of the queen and the pheromone physics have to be adequate to ensure proper building of the queen chamber.
The following series of images shows how the wall building evolves:
The presented NetLogo simulation was written by:
Thomas Schmickl (2002), Department for Zoology, Karl-Franzens-University Graz, Austria, Europe, email@example.com, firstname.lastname@example.org
- Camazine S., Deneubourg J.-L., Franks N.R., Sneyd J., Theraulaz G. and Bonabeau E. (2001) Self-Organization in biological systems. Princeton
- Resnick M. (2000) Turtles, termites and traffic jams. MIT Press.
- Bonabeau E., Dorigo M. and Theraulaz G. (1999) Swarm intelligence. From natural to artificial systems. Santa Fee Institute studies in the sciences
of complexity. Oxford University Press