Silverfish are small, fast-moving insects that live in dark places such as drawers, bookshelves and cupboards. They consume cellulose--an insoluble substance that gives plants their structure--and according to Texas A&M University, they also eat carbohydrates, such as oats and flour, and protein, such as dried meat. They can damage the pages and bindings of books that don't see much use, and will consume old newspapers, fabric, exposed artwork, posters and even wallpaper. Some common household spices are known to discourage these pests.
According to ABC Tasmania, silverfish are repelled by the scent of cloves. Whole cloves are best, as they retain their odor longer. Place them in drawers, closets and anywhere else silverfish may spend their time. Cloves may lose their smell over time, depending on their original freshness. Refresh the cloves whenever their smell dissipates. According to the University of Nebraska-Lincoln, stored spices lose freshness after a year or two, though cloves outside the bottle will lose their effectiveness more quickly. Objects stored in the vicinity of cloves may take on a spicy smell.
More commonly used to flavor fish dishes or in baking, citrus peel contains a chemical called d-limonene. This substance is not dangerous to humans, but repels a number of insects, including silverfish. Strew fresh citrus peel in areas frequented by silverfish, or simply apply citrus oil, such as lemon or orange essential oils, to the area. The result is a fresh-smelling closet or drawer and fewer silverfish.
The leaves of the bay laurel, a European evergreen, make an excellent addition to soups and stews. They're also thought to repel insects. Robin Stewart's Chemical Free Pest Control recommends using whole bay leaves in areas where silverfish may be a problem. As with cloves, bay leaves become less effective as they get older. Refresh the leaves whenever their smell starts to disappear--usually every few months. Bay may need to be replaced more often in hot or humid conditions.
This sweet-smelling spice is used in teas, to make lavender butter and in a number of other foods. It's also a traditional remedy for insect infestations of all kinds. According to Robin Stewart, lavender can be used whole, or blended into beeswax and applied to the surface of cabinets, bookshelves and closets. Lavender is a traditional laundry scent and may keep silverfish out of stored linens. However, synthetic lavender scents won't do the trick--be sure to use the actual spice.
Chrysanthemum tea is popular in China and East Asia as a beverage and medicinal treatment. Chrysanthemums also contain chemicals called pyrethrins. These substances are largely harmless to humans, but can cause damage to insect nervous systems. In fact, pyrethrins from chrysanthemum are used to make many of the natural pesticides on the market. Consider using chrysanthemum flowers or their extracts to control silverfish. Fresh flowers are generally more effective than dried ones. The University of Nebraska-Lincoln notes that neurological effects from pyrethrins can be short-lived and do not usually kill the insects on their own.