Researchers Reveal a Hidden Biological Clock in Insects

University of Cincinnati researchers found that fruit flies, mosquitoes, kissing bugs, and spider beetles synchronize their daily behavioral rhythms to humidity cycles, with insects continuing the pattern even after the humidity signal was removed, adding humidity to the known environmental cues that entrain circadian clocks.

Humidity's influence on insects was weaker than light or temperature; any potential effect on human circadian timing would likely be too subtle for people to notice.