I came across one of these interesting insects while hiking in Santa Cruz, California. I occasionally find them in my home state of Ohio as well. In fact, lately they seem to be hanging out in the storage section built into the seats of our plastic deck chairs.
Earwigs have characteristic cerci, a pair of forcep-like pincers on their abdomen, and membranous wings folded underneath short, rarely used forewings, hence the scientific order name, Dermaptrea, which translates to “skin wings.”
Adults can use the cerci in defense, twisting the abdomen forward over the head or sideways to engage an enemy, often another Earwig. The pronounced cerci are the most distinctive feature of Earwigs; in the male the cerci are strongly curved whereas in the female they curve only slightly.
These insects are small (about 1/2 an inch long) and mostly nocturnal. They often hide in small, moist crevices during the day, and are active at night, feeding on a wide variety of insects and plants. They tend to be more common in the southern and southwestern parts of the United States.
Earwigs can also be found throughout the Americas and Eurasia. The Common Earwig was introduced into North America in 1907 from Europe; it was first observed in North America at Seattle, Washington in 1907. It spread quickly, and was reported in Oregon in 1909, British Columbia in 1919, and California in 1923. It reached Rhode Island in 1911, New York in 1912, and most other provinces and northern states in the 1930s and 1940s.
Earwigs are among the few non-social insect species that show maternal care. The mother pays close attention to the needs of her eggs, giving them warmth and protection. She dutifully defends the eggs from predators, not leaving them even to eat, unless the clutch goes bad. She also continuously cleans the eggs to protect them from fungi.
Earwigs are mistakenly thought to enter the ears of sleeping persons and burrow into their brains. This is an urban myth that has no basis in fact. In reality, these menacing-looking insects are totally harmless.