I'd like it if silverfish spawned in dark, wooden, damp areas of your house, where the light level is sub-par, water is dripping from above, next to an ocean, lake, or river, etc. When they eat paper or wooden blocks you'd see the breaking blocks particles being emitted and the eating sound. Bookshelves would drop 1 or 2 books and 3-4 planks when eaten, planks would drop 2-3 sticks when eaten.