# Termites 3D

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### WHAT IS IT?

This is a 3D version of the Termites model. This project is inspired by the behavior of termites gathering wood chips into piles. The termites follow a set of simple rules. Each termite starts wandering randomly. If it bumps into a wood chip, it picks the chip up, and continues to wander randomly. When it bumps into another wood chip, it finds a nearby empty space and puts its wood chip down. With these simple rules, the wood chips eventually end up in a single pile.

### HOW TO USE IT

Click the SETUP button to set up the termites (white) and wood chips (yellow). Click the GO button to start the simulation. The termites turn orange when they are carrying a wood chip.

The NUMBER slider controls the number of termites. (Note: Changes in the NUMBER slider do not take effect until the next setup.) The DENSITY slider controls the initial density of wood chips.

### THINGS TO NOTICE

As piles of wood chips begin to form, the piles are not "protected" in any way. That is, termites sometimes take chips away from existing piles. That strategy might seem counter-productive. But if the piles were "protected", you would end up with lots of little piles, not one big one.

The final piles are roughly round. Why is this? What other physical situations also produce round things?

In general, the number of piles decreases with time. Why? Some piles disappear, when termites carry away all of the chips. And there is no way to start a new pile from scratch, since termites always put their wood chips near other wood chips. So the number of piles must decrease over time. (The only way a "new" pile starts is when an existing pile splits into two.)

This project is a good example of a DECENTRALIZED strategy. There is no termite in charge, and no special pre-designated site for the piles. Each termite follows a set of simple rules, but the colony as a whole accomplishes a rather sophisticated task.

### THINGS TO TRY

Do the results change if you use just a single termite? What if you use several thousand termites?

When there are just two piles left, which of them is most likely to "win" as the single, final pile? How often does the larger of the two piles win? If one pile has only a single wood chip, and the other pile has the rest of the wood chips, what are the chances that the first pile will win?

### EXTENDING THE MODEL

Can you extend the model to have the termites sort several colors of wood?

Plot the number of piles, or their average size, or the number of termites carrying wood chips, as the model runs.

### NETLOGO FEATURES

Notice that the wood chips do not exist as objects. They are just represented as colors in the patches. The termites update the patch colors as they pick up and put down the wood chips. In effect, the patches are being used as the data structure. This strategy is useful in many NetLogo programs.

Note than when you stop the GO forever button, the termites keep moving for a little while. This is because they are each finishing the commands in the GO procedure. To do this, they must finish their current cycle of finding a chip, finding a pile, and then finding an empty spot near the pile. In most models, the GO function only moves the model forward one step, but in this model, the GO function is written to advance the turtles through a full cycle of activity. See the "Buttons" section of the Programming Guide in the User Manual for more information on turtle forever buttons.

### RELATED MODELS

Shepherds, Painted Desert Challenge

### HOW TO CITE

If you mention this model in an academic publication, we ask that you include these citations for the model itself and for the NetLogo software:

- Wilensky, U. (2002). NetLogo Termites 3D model. http://ccl.northwestern.edu/netlogo/models/Termites3D. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

- Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

In other publications, please use:

- Copyright 2002 Uri Wilensky. All rights reserved. See http://ccl.northwestern.edu/netlogo/models/Termites3D for terms of use.

### COPYRIGHT NOTICE

Copyright 2002 Uri Wilensky. All rights reserved.

Permission to use, modify or redistribute this model is hereby granted, provided that both of the following requirements are followed:

a) this copyright notice is included.

b) this model will not be redistributed for profit without permission from Uri Wilensky. Contact Uri Wilensky for appropriate licenses for redistribution for profit.

This is a 3D version of the 2D model Termites.

This model was created as part of the projects: PARTICIPATORY SIMULATIONS: NETWORK-BASED DESIGN FOR SYSTEMS LEARNING IN CLASSROOMS and/or INTEGRATED SIMULATION AND MODELING ENVIRONMENT. The project gratefully acknowledges the support of the National Science Foundation (REPP & ROLE programs) -- grant numbers REC #9814682 and REC-0126227.

## Comments and Questions

turtles-own [task steps] to setup ca ask patches [ ;;randomly distributes wood chips if random-float 100 < density [ set pcolor yellow ] ] crt number [ ;;randomly distributes termites set color white setxyz random-xcor random-ycor random-zcor tilt-up random 360 right random 360 set task 0 set steps 0 ] ask turtle 0 [ set size 2 ] end to go ask turtles [ wiggle ifelse steps > 0 [ set steps steps - 1 ] [ do-task ] ] tick end to wiggle ;; turtle procedure fd 1 right random 20 left random 20 tilt-up random 20 tilt-down random 20 end to do-task ;; turtle procedure ifelse task = 0 [ search-for-chip ] [ ifelse task = 1 [ find-new-pile ] [ ifelse task = 2 [ put-down-chip ] ;; task = 3 [ get-away ] ] ] end to search-for-chip ;; turtle procedure -- "picks up chip" by turning orange if pcolor = yellow [ set pcolor black set color orange set steps 20 set task 1 ] end to find-new-pile ;; turtle procedure -- look for yellow patches if pcolor = yellow [ set task 2 ] end to put-down-chip ;; turtle procedure -- finds empty spot & drops chip if pcolor = black [ set pcolor yellow set color white set steps 20 set task 3 ] end to get-away ;; turtle procedure -- get out of yellow pile if pcolor = black [ set task 0 ] end ; Copyright 2002 Uri Wilensky. All rights reserved. ; The full copyright notice is in the Information tab.

There are 3 versions of this model.

## Attached files

File | Type | Description | Last updated | |
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Termites 3D.png | preview | Preview for 'Termites 3D' | over 10 years ago, by Uri Wilensky | Download |

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