170 likes | 197 Views
Explore the "Ants" simulation to compare behaviors with real ants, experiment with simulation properties, and delve into density-dependent turning values.
E N D
Computational Representation of Ant Foraging Clayton Lewis June 26, 2010
Find and Download the “Ants” Simulation • from the scalable game design home page, • click “Summer Institute 2010” • then “STEM Simulations” • then “Ants” • then “complete” to download Agentsheets Project
Explore • Run the complete simulation, and see what features of the behavior of the simulated ants you can identify. • At this stage, don’t examine the rules, or modify simulation properties. • Run the simulation fairly slowly at first so as to be able follow the behavior of individual ants. • Think about the brown markings as trails, not tunnels.
Discussion • How do these behaviors of the simulated ants compare to those of real ants?
Thought Questions about Real Ants • How do they find their way back to the nest? • Why could it be useful for the trail pheromone to evaporate?
Exploring Variations • The simulation property “ticks” measures how quickly the ants have exhausted the food. • The simulation property “turning” controls how often ants turn when foraging • Let’s use these properties to explore what value of turning works best
Exploring Turning • We’ll create a simple food layout • Use the arrow tool and move the nest to the middle of the worksheet • Erase the food • Place 4 lollipops a little way NE,SE,SW, and NW of the nest • Erase the ants and put 4 in next to the nest, E,S,W,N • SAVE the worksheet
Exploring Turning (Cont.) • We’ll assign values of “turning” by counting off: 10,50,90 • Reset your simulation • Set the value of turning to your value in the Simulation Properties Window • Run the simulation • Report the value of ticks when all the food is gone
Exploring Turning (Cont.) • Let’s change food layout • Use the arrow tool and move the food near the corners of the worksheet • SAVE • Check that your simulation properties window shows your value of turning, and ticks 0 • Run the simulation again with your value of turning
More Explorations What is the effect of pheromone life? Does it depend on the amount of food at a food site? Does this effect depend on number of foragers? Does the optimal turning value depend on the number of foragers?
About the Program • The program uses several computational thinking patterns: • collision (ant and food) • diffusion (distance to nest) • hillclimbing (to find nest) • polling (to control ticks) • These and many others are described on the Wiki
Extending/Changing the Program • What if there is no pheromone trail? • (Try it… first find the rule that places the trail… a little tricky!) • The ants don’t follow the trail perfectly… can you (or your students) improve this? • Some real ants don’t begin to search until they have moved some distance straight from the nest…(why?) … could you add this feature?
Ant Tournament • Students can be challenged to produce improved ants that forage more quickly • …and to research how their improvements relate to real ant foraging
Final Words • Real ant researchers use simulations to understand ant behavior… • … and some computer scientists study ants to understand new ways of searching for information. • More ant materials are on the Wiki