This makes sense because an organism will first learn to obtain food and water before it tries other more frivolous pursuits.
Fear conditioning is a behavioral paradigm in which organisms learn to predict aversive events.
But it could also be that other planetary organisms would learn of their presence by this "spoor" left in space.
Also, organisms tend to have a normal biological developmental pathway as a central nervous system ages and/or learns.
Classical conditioning: where two stimuli come together, the organism learns they are related.
In simplest terms, the reorganization process varies things until something works, at which point we say that the organism has learned.
If the two stimuli are often presented together, the organism learns that they belong together.
The organisms had learned to live on 2,4,5-T, one ingredient of the infamous Agent Orange.
With experience, organisms can learn to make finer perceptual distinctions, and learn new kinds of categorization.
When organisms learn naturally it is usually through a mixture of these and other slightly different types of learning.