There is my answer, great idea! Thank you million times over!cut........
Grain mites -- drop that humidity quick! Bake a new batch of substrate and place it in a clean new box; sort out your live mealies and beetles, transfer to a colander/screen thingie and gently rinse with barely tepid water. Dump onto thick paper towels, blot gently, and slide them into their new digs. Keep the new digs as dry as possible--feed small amounts of veggies less frequently, and make sure there's plenty of ventilation.
Good luck!