Earwigs are a little tricky when it comes to being a pest or not. They eat aphids and other garden pests, so I usually don't try to control them unless their population is extremely high and the birds and toads have not been eating them fast enough. If you have a lot of birds in your yard, you most likely will not have a bad case of earwigs.
Earwigs are about a half an inch long and are brown or reddish brown. They have two antennae on one end and little pinchers on the back end. You can view some pictures of earwigs here.
If you have earwigs in high numbers in your yard, they could get into the house where they will eat house plants and feed on greasy or sweet foods.
Earwigs are generally nocturnal, so you may not notice them during the day. They are attracted to damp shady conditions, so keeping plantings away from the foundation of your home can help to prevent them from getting inside. They like to eat smaller insects, organic matter and munch on the foliage of strawberries, lettuce, marigolds and dahlias as well as some other plants. Since they feed on the roots as well as the leaves of these plants, they can kill young plants pretty quickly if they are in high numbers.
To control earwigs in your home, spread diatomaceous earth around the outside foundation of your home to prevent them from getting inside. Their pinchers may give you a slight nip, but do not usually break the skin. They are basically harmless to humans and are not poisonous.
To control earwigs in the garden, remove any leaf litter in shady areas. You can also create a trap by mixing 1 tablespoon dry yeast, 1 tablespoon molasses, 1 tablespoon vegetable oil, and 8 ounces of water. Place the mixture in a shallow bowl and bury it to ground level. The earwigs will be attracted to the mixture, they will eat it and die due to the yeast swelling up in their bellies. Remove the earwigs from the mixture daily.
Helen from Toronto Gardens offered this tip on my blog. She writes,
"Dottie, Earwigs are also attracted to long narrow hiding places. For instance, they like to hide overnight in the ends of bamboo garden stakes or grooves in cedar fencing. One relatively easy control is to scatter small squares of corrugated cardboard in areas where there's plant damage, then gather up the squares in the morning and drop into a garbage bag or a pail of soapy water".
Again, I really do not consider earwigs as a major pest in my garden since they do eat so many garden pests, but I realize they can be pretty damaging in high numbers. If you have stopped using chemical herbicides and pesticides in your garden, the birds and toads will be in higher numbers and therefore should take care of their population all on their own.