There is nothing to suggest that the insects consider their behaviour. When insects do something that looks reasonable, it is due to the innate, appropriate behaviours – that are built into their nervous system – that are triggered under certain conditions in response to certain environmental influences. Most of our knowledge about the storage pests’ biology and behaviour derives from laboratory tests, where the results are indicative only. The fact is that local populations of any given species can develop their own characters.

Due to short average insect lifetime, the individual insect will probably not adapt to changes. Any adjustments will be the result of natural selection. Individuals that have qualities that fit the available conditions best survive and have the most offspring. An example of such an adaptation to changing conditions through natural selection is that many insect populations have developed resistance to one or more of the toxins with which we treat their habitats. The individual only has very limited opportunities to change behaviour during its lifetime. However, there are examples where insects have learned to stay away from places where they are exposed to unpleasant experiences.