 Following feeding, most insects retain enough water to completely hydrate their bodies, excreting the remainder.However, the amount of water excreted differs between species, and depends on the relative humidity and dryness of the environment.For example, Tsetse flies maintained at a high relative humidity, and thus non-arid conditions, excrete fecal matter with approximately 75% water content, whereas Tsetse flies maintained at a low relative humidity, and thus dry conditions, excrete fecal matter with only 35% water content.