What should i do? (guineapigs)?

Well, I don't know what an earwig is, but our guinea pigs were infested with largish fruit flies...zillions of them. We used food grade diatomaceous earth (DE) and sprinkled it in the cages, around the edges, and especially on damp spots where flies like to lay their eggs (it kills the eggs). We are down to only a few flies per day now. DE is safe, non-toxic to animals, and is put in food for some animals. You can get it at a feed store. Good Luck!