Which of the following methods can help reduce humidity levels that pests thrive in?

Improving sunlight exposure is an effective method for reducing humidity levels in environments where pests thrive. Sunlight raises the temperature of the area, leading to increased evaporation of moisture from the soil and surrounding surfaces. This reduction in moisture can create less favorable conditions for many pests which prefer humid environments to thrive and reproduce.

In contrast, increasing plant cover can actually provide more shaded areas where humidity can accumulate, while the use of mulch may retain moisture in the soil, further contributing to higher humidity levels. On the other hand, selectively planting shade-loving plants will create more shaded spots, which can again increase humidity in those areas. Thus, enhancing sunlight exposure is key to minimizing humidity and making the environment less hospitable for pests.