The CA is controlled by the following buttons:

Hide CA-2
 Makes CA shorter.
Longer: Makes CA longer.
Plant CA-1: CA-1 is planted.
Plant CA-2: CA-2 is planted.
Small CA-1:  make CA-1 smaller
hungry: CA-2 adds some of its bits to CA-1 (perturbs it), which happens only when they touch each other.

Resources=  the amount of resources the CA has
Size:  Maximal CA size
interaction: indicates when the CA meet.

When the experiment   begins  the two CA start moving up and down. Both bounce back from  the borders. Their resources decline at a rate of 1 unit / time unit and they get thinner.  When they touch or overlap (interaction = true) their  resources are replenished  and they grow. Resource accumulation is proportional to  CA size. The fatter the  CA become  the more resources they  accumulate.

Their aim is to accumulate resources, grow and attain  their default solution (attractor) which they can realize only by touching each other.  Each encounter raises the probability to reach this goal. The probability depends on four factors.
1. Resources (r). The higher their resources the bigger they get,  improving their chance to meet. 
2. Size (s) is proportional to  resources.
3. Velocity (v)  is inversely proportional to size and resources.  As the CA loses resources it moves faster to find a companion.
4. Interaction duration (d). In big CA the encounter lasts longer. If this is not enough, CA-2 gets hungry (hungry = true), perturbs CA-1, hijacks it and prolongs their interaction.
The probability p(r, s, v, d, t) is monotonic  and will ultimately become p = 1. (t: time)

The smaller the CA get the more difficult it will be for them to grow. Nevertheless they will succeed. They may need several encounters to start growing yet with each encounter their chances improve.  At times they may attain their default structure (size=24) even  when separated, yet this solution is unstable. Soon they will lose resources and start moving again.  In order to form a stable solution they have to cooperate! Only then  will  they   bring about  the three conditions for a success: 
1. Touching each other (interaction = true)
2. Maintaining a size of 24.
3. CA-2 is sated with resources  (hungry = 0)