Are you sure they aren't goldfish? Color is the best way to tell them apart.
Since you called them fritters, you are probably aware that they can be killed by sautéeing in batter cakes. Before doing that, please remember that silverfish are our friends because they eat mold.
They also eat human food and paper products. Keep your kitchen clean and don't bring any books home from school. They like natural textiles, so get synthetics. They need damp places, so keep everything dry.
You can use a bulb to blow dessicant powder into the places they hide.