How to tell you have them
Silverfish are flat, about half an inch long, carrot-shaped and covered in silvery scales, with two long antennae and three bristles at the tail. They run fast and wriggle like a fish. You usually meet them at night or when you move a box in the garage, closet or attic, or find one trapped in the bathtub. Their close relative, the firebrat, looks similar but mottled, and prefers hot spots near water heaters and dryers.
What they damage
They eat starch and protein: paper, book bindings, glue, wallpaper paste, photographs, cereal, flour and natural fabrics such as cotton and linen. The damage looks like irregular holes and surface grazing, often with yellowish stains. Stored documents and boxes in a humid garage are the usual casualties.
What treatment looks like
Silverfish need humid air, roughly above 75 percent, so the most lasting fix is drier air: run the air conditioning, use a dehumidifier in closets and bathrooms, vent the dryer outside and fix plumbing drips. We treat the cracks, baseboards and voids where they hide with a crack and crevice product, apply dust in attics and wall voids where the label allows, and suggest moving stored paper into sealed plastic bins off the garage floor.
How long it takes
Most homes see a clear drop within two to four weeks, once treatment and humidity control work together. Silverfish live for years and lay eggs over months, so the quarterly visits keep the treated areas current.
Florida notes
Pinellas humidity stays high most of the year, and homes closed up with the air conditioning off while the owners travel are classic silverfish homes. Older bungalows with attics full of stored boxes need the most attention. Silverfish are covered on every plan, starting with Quarterly.