1. Are they silverfish or firebrats?

The first thing to determine is whether you have silverfish or firebrats.

Silverfish are gray to green in color and prefer temperatures around 80°F while firebrats have a mottled black and white appearance and like it hotter at a toasty 100°F.

2. Eliminate the sources of the infestation

Preferred environments

Silverfish thrive anywhere moisture is high - under sinks, around leaks, bathrooms, kitchens, attics, piles of leaves and mulch, and anywhere there is standing water. Firebrats also like humidity but are usually found in warmer areas - laundry rooms, in and around stoves, water heaters, bookshelves, and books. Silverfish control begins by reducing excess moisture as much as possible by fixing any leaky plumbing, setting up dehumidifiers or strategically deploying a desiccant such as Drione dust. Excessive dryness will kill silverfish and firebrats.
These insects always stay close to their food source, so if you see one you know food isn’t far off.

Food sources

Both silverfish and firebrats eat protein, sugars and starches but they greatly prefer starches. They will eat pastes, glues, book bindings, paper that contains glues, wallpaper pastes, starched fabrics, silk, cereals, and certain synthetic fibers. Clean any areas that you believe to be infested and use silicone caulk to seal up any cracks or crevices in which lint accumulates.

Characteristic feeding marks are tiny, irregularly-shaped scrapings, holes and notches. They will often eat their way through wallpaper to get at the paste, and leave yellow stains on fabrics.

Points and methods of entry

These insects are usually brought into the house in packaged goods, boxes and bags that were previously stored in a moist or humid environment.

3. Silverfish extermination

If you are having trouble figuring out where your infestation is centered, you can find out by deploying some home made bait. Gather together a bowl, some index cards, flour, water and a soft brush then follow these steps:

1. Fill the bowl with a cup of water and begin mixing in flour until you have a paste with a consistency similar to thin paint.
2. Coat both sides of several index cards with the mixture and allow them to dry.
3. Place the dried index cards in areas believed to be frequented by the silverfish or firebrats.

If they’re around, they will be attracted by the starchy coating on the cards and will feed on them. Leave the cards in place for a week and then examine them for signs of feeding; small, irregularly shaped scrapings and notched edges. Dark food coloring can be added to the mix to make scrapings more visible.

Books

Infested books can be sealed in a plastic bag along with some desiccant and placed inside of the freezer for three days to kill any resident silverfish and firebrats. If your book case has become infested, consider spreading some diatomaceous earth behind the books on the shelves to keep the moisure levels down and kill any paper-eating insects that may be hiding out.

Traps

Home made jar trap
A very simple trap can be made by taking some canning jars, scrubbing them absolutely clean and then covering the outside with masking tape to make them easy to climb. These traps are then placed out in areas of infestation. The bugs will climb up and fall into the jars and then will not be able to climb the smooth interior walls to escape. Moist cotton or starchy foods work as bait but are not needed.

Sticky roach traps
Sticky roach traps can be used to catch both silverfish and firebrats. These can be found online and at your local hardware store.

Poisons

The only poisons recommended for killing silverfish and firebrats are insecticidal dusts such as diatomaceous earth and Borax. These should be used in cracks, under and behind furniture and appliances, and inside walls and crawlspaces. Keep these out of your breathing air and inaccessible to both children and pets.