There are numerous ways to kill silverfish, including the use of boric acid and diatomaceous earth. Silverfish can be captured and killed using glasses wrapped in masking tape and filled with sugar water as bait. Another way to get rid of silverfish is to spray a mixture of bleach and water in the areas where they live or points where they access a home. The best way to control silverfish is to make one's home inhospitable to these insects.
Boric acid is an effective means of silverfish extermination, though it's a low-grade toxin. Children and pets must be kept away from areas in which boric acid is used. The powder should be sprinkled where silverfish have been noticed. Particular attention should be paid to areas where silverfish like to hide, such as under sinks and in cracks and crevices. More boric acid can be sprinkled every two weeks as needed to kill silverfish.
Another way to kill silverfish is to use food grade diatomaceous earth, a powder that is nontoxic to mammals but lethal to insects. Composed of the fossilized remains of phytoplankton, diatomaceous earth gets caught in the crevices of an insect's exoskeleton, and as the insect moves, the particles act like blades to slice it up. To control silverfish, diatomaceous earth should be placed in areas where silverfish have been noticed and where they can hide.
One can build a silverfish trap by filling a glass or a jar halfway with water, to which two or three teaspoons of sugar are added as bait. The glass or jar should be wrapped with masking tape so that silverfish can climb up the sides to access the sugar water. When the silverfish fall in, they will die because they cannot climb up the slick interior sides of the glass or jar to get out.
Bleach is an effective way to kill silverfish. A person can mix, in a spray bottle, one part bleach with two parts hot water. To get rid of silverfish, othe areas where they live and crevices in which they hide can be sprayed with the bleach and water mixture every two or three months. Another tip is to pour the mixture down drains to kill silverfish that may be crawling up pipes and seeking entry into a house.
The best way to control silverfish is to make a house as inaccessible and inhospitable to them as possible. Cracks in a home that allow them access must be sealed. Silverfish eat mold and mildew, which is made worse by moisture and humidity, so a home can be made less appealing for silverfish through the use of dehumidifiers and air conditioners. Large stacks of paper should be thrown away, since they are both a hiding place and a food source for silverfish. Salt and cloves, which silverfish try to avoid, can be placed in trouble spots or at access points to the home.