The CA is controlled by the following buttons:

Plant CA: CA is planted.
Shorter: Makes CA shorter.
Longer: Makes CA longer.

The obstacle is controlled by the following buttons:
Upward: Moves obstacle upward. Its y-coordinate is displayed as ycoord =.
Downward: Moves obstacle downward. Its y-coordinate is displayed as ycoord =.

No movement:
width+: Make CA wider
width-: Make CA slimmer

Resources= the amount of resources the CA has.
ycoord= The y-coordinate of the obstacle
Width: CA width

This is a continuation of the foraging experiment . When the experiment starts, a zygote is planted at  the applet bottom which is the CA nest. As the CA grows it loses resources and after it matured it turns upward toward the obstacle which serves as its food. When clinging to the food source (obstacle) it may create a new solution and changes its structure. After accumulating  about 40 resource units it turns back to explore  its nest neighborhood. When resources = -150 the CA  plants a zygote and dies.

In the following experiments first change width and then plant the CA

Start from width =  12 and after each run make the CA thinner.  

Width	Behavior
2	Does not return to the nest
3	No movement
4	When turning  back it creates a new solution
5	When turning  back it creates a new solution
6	Does not return to the nest
7	Extremely slow
8	Returns to the nest
9	Returns to the nest
10	Returns to the nest
11	Does not return to the nest
12	Returns to the nest
16	Returns to the nest
24	Default structure   CA is isolated

Each width determines a different CA solution, or structural attractor. Interaction with the obstacle, perturbs the CA and it attempts to create a new solution. If failing it plants a new zygote and dies. The behavior of CA with width > 12 is more complex. Nevertheless they all seek a solution. Try width = 16. Despite complex behavior the CA will reach the obstacle and return to its nest.

Set width = 16.  The system as a whole consisting of the two CA will oscillate around its center of mass and occupy an attractor. You might regard   it as a solution of a two body problem in which a constant CA interacts with a moving one..