Earwigs are 1/4 to 5/8 inch long with tan, brown, and black coloration. Most species have large forcepslike pincers (called cerci) at the posterior end of the abdomen. They have membranous hind wings folded up beneath small leathery forewings and are capable of flying, though they rarely do. The European earwig is the most important structure-invading earwig species.

While earwigs tend to hide in dark, moist crevices, they do not crawl into ears. They are active at night and hide during the day. Earwigs are scavengers that feed on decaying plant and animal matter, but they will also feed on household items such as flour and bread. Female earwigs care for the young, which is a very unusual characteristic in the insect world. Females will guard and clean the eggs and watch over and feed the hatchling earwig nymphs until they molt. It is common to find many earwigs hiding together.

Earwigs may enter a structure in large numbers and can then get into everything from food to laundry. They do not cause direct damage to people or structures, but they may occasionally cause some economic agricultural damage.