Silverfish Problems: Can I use boric acid to fight silverfish by having pets at home?

Silverfish Problems: Can I use boric acid to fight silverfish by having pets at home?


Can i use boric acid to fight silverfish by having pets at home?


Good morning,

I would have to ask about the silverfish insects in the house. I moved a few months ago and for two months I have noticed silverfish every now and then in the two bathrooms. This month, however, I notice a few more minnows in the bedroom carpet (parquet) and still with moving boxes. I removed everything but found some near the living room skirting board and 2 on the sofa. Now I am putting hidden morsels with bread, sugar and diluted boric acid and I saw a little fish this morning that was lured. Since I have pets, I ask if with the boric water solution spray I can pass skirting boards, windows and doors, closing them for a few hours in another room, ventilating them and then returning them to the rooms. I would like to do this now before buying more furniture in the living room and bedroom. To pass the boric acid, is it better if I remove the skirting boards and put them back? I have underfloor heating. Could it be a problem?

Thanks for your attention.

Best regards.



Hi Patrizia,

first of all I suggest you to know the physiology of silverfish well (the scientific name is Lepisma saccharina) to understand how to deal with them. For this reason, I refer you to the answer I gave to Sara that you will find on this page. After that, let's try to reason together. Since you have recently moved home, the best thing to do would have been to rely on a specialized company that would have solved the problem with special fumigations. But in hindsight, it's not going anywhere.

The fact that you have pets limits the interventions you can do. In fact, you must be very careful in the use of boric acid since, although it is not poisonous, if ingested in quantity, it can give serious problems and whether it is dogs or cats, with the habit of licking where it happens or licking themselves after lying on the ground where there may be traces of boric acid, could cause serious problems to their health.

You could do this: work room by room. Let me explain. I would use the jet of steam added with boric acid in a closed room, obviously keeping the animals away. I would pass it everywhere: behind the skirting board, in the boxes of the blinds ... in all the most unthinkable corners and I would close the room and leave it like that for a couple of days. After that I would clean everything well to leave no residues of boric acid and I would reopen it. Then I would move to another room and so on. If this is not possible, then I would only use the jet of steam which however has its effectiveness even if more limited.

Put sugar and boric acid baits on a white sheet of course in places your pets can't get to.

If the skirting board is made of wood, and is one of the rounded ones that do not adhere to the wall, there will certainly be a large concentration of silverfish behind it, so it is advisable to remove it to disinfect well. It would be much better to change it with a material other than wood (ceramic, stone, etc.) and above all that it adheres well to the wall so as not to leave spaces in which silverfish can nest.

This is all I can advise you. But I think that in this way you will be able to contain them and keep them under control (obviously repeating everything periodically).

If I have not been clear, write me again.

Dr. M. G. Davoli


Hello, I have only one last doubt, I think I will not be able to close the kitchen / living room ... I should do it in a few hours and then reopen it. As well as my bedroom. Also I dissolved 30gr of boric acid in a liter of water but I use it with a spray, I would have the vaporetto ... better if I use that? Can it still work? I thought about putting ceramic baseboards to acquire the problem. However, I notice that for a day after cleaning the empty bedroom, corridor and after having properly grouted the bathroom tiles I have not seen even one.

I hope that in the kitchen / living room it will have the same effect even if I can leave it on for a few hours and then clean ...

I have to do the treatment periodically ... but forever? Or for a few months? Thanks and sorry again ... but the anxiety of not getting rid of it is great even though I know it will take patience.

Thanks to the availability.



Hi Patrizia,

the vaporetto is much better. In this way you add the action of the boric acid to that of the vapor. Furthermore, the idea of ​​ceramics for the ceramic skirting board is a winner against the silverfish.

If it is not possible for you to keep the rooms closed longer after the treatment, even a few hours is fine. However, always take into account the thorough cleaning of the room before letting your pets in.

The frequency of this treatment is dictated by the quantity of silverfish that are present / that remain inside the house. Of course with this treatment and changing the skirting board you will solve a lot but it will be very difficult to eliminate them completely. You will evaluate the periodicity based on how many you will see running around the house. However, keep in mind that with someone who goes around the rooms you will have to learn to live together. At my house, I do the treatments I told you about every six to eight months, only having libraries practically all over the house, I can't completely eliminate them so in the end, I have learned to live with them.

Good luck.

Dr. M. Davoli