There are several natural ways to kill silverfish, including:

• Diatomaceous Earth: This powder is made from diatoms - the fossilized remains of tiny aquatic organisms. When silverfish come in contact with diatomaceous earth, they die of dehydration.

• Boric Acid: Boric acid is an inexpensive, simple, and readily available household cleaner that can help remove silverfish. It will not only kill the silverfish but also their eggs, preventing any further infestation. However, it is harmful to the lungs, so it is important not to inhale it.

• Cedar Shavings: Cedar oil and shavings are a common natural insecticide. Silverfish are repelled by the woody smell of cedar, so putting cedar shavings and/or oil in the infected areas can help get rid of them.

• Citrus Fruits: Silverfish are repelled by the smell of citrus fruits. You can use orange and lemon peels to keep them at bay. Keep the fruit peels in the places which you think are infested and change them after some time.

• Cinnamon: Silverfish hate the smell of cinnamon. Once they realize the presence of cinnamon, they will leave your house alone. You can sprinkle cinnamon powder in the infested areas or use cinnamon oil.

• Salt: Silverfish are attracted to salt, but eating it will cause them to become dehydrated and die. Salt will also absorb damp in the area.

• Essential Oils: Essential oils of peppermint, tea tree, cinnamon, eucalyptus, and lavender have insect-repelling properties because of their concentrated odor. You can drop the essential oil where youve spotted silverfish or make a simple spray with water and 20-30 drops of oil.

• Oatmeal Trap: You can make an oatmeal trap by taking a glass jar and covering its outer surface with a tape to make it easy for the silverfish to climb up. Then, put 1/2 cup of powdered oatmeal in the jar. The silverfish will climb up the jar to eat the oatmeal and get trapped inside.

It is important to note that these natural remedies may not completely eliminate a silverfish infestation. If the infestation is severe, it is advisable to seek the help of a pest management professional who can use an approved insecticide and their specialist knowledge of the pest’s behavior to control silverfish.