Earwigs got their name from the superstition that they crawl into a person's ear and eat their brain. While this is certainly an old wives' tale, large infestations of earwigs can harm plants. They seldom cause enough damage to be worth eradicating in small numbers. Earwigs are insects with large pinchers on their abdomen. They can use them for defense by curling the pinchers over their back. Boric acid can be used to kill them both indoors and outdoors.
Punch several holes in the sides of a small, flat box using a hole punch. You can punch the holes using a large nail if the box material is too thick for a hole punch. These are the holes the earwigs will enter through, so make them close to the bottom edge of the box.
Add about a tablespoon of dry oatmeal to the bottom of the box.
Sprinkle a light dusting of boric acid over the oatmeal.
Put the lid on the box, and place the box on the ground near locations where earwigs have been spotted.
Cover the box with a board to keep it from getting wet.