ABSTRACT
This chapter discusses that rainwater is defined as precipitation that has not been in contact with the soil, ground water, or bodies of standing or flowing water, which are, in turn, in contact with a substrate that is not impermeable to water. In natural water bodies, insects must survive in the presence of many natural enemies, pathogenic microorganisms, chemical pollutants, and sometimes even acute shortages of oxygen. A few structures that catch and hold rainwater are found among natural rock. Naturally hollowed out rocks are found in many parts of the world, but they are not abundant. However, human beings have greatly increased the number of habitats similar in shape and size to such natural rainwater containers suitable for the larval development of aquatic insects preferring rainwater over the water in ponds and lakes. Artificial containers to hold rainwater for long periods of time include various objects stored near human habitations.
