Since a few weeks, I got a small slug infestation. Since I have a large, glass sliding door at the back of my house which the snails seem to like, it gets covered in slugtrails and slugexcriments. Needless to say, I'd like to prevent this. During the night, about 20 different slugs traverse on my glass doors and are all gone when morning comes.

Question is how I can prevent these buggers to slime on the glass doors in the first place?

I have tried to "humanely" kill them off with saucers of beer... But it seems they are just partying the night away, because none are left dead in the morning. I know about the salt thing, but since there are so many, I don't think killing a few off every evening is going to do the trick.

  • @RichardBernards: we can help you better if you post a picture of the lower part of the sliding doors, on the outside. We need to see the angle between the floor / ground and the door / door frame.
    – virolino
    Commented Sep 2, 2020 at 5:30

5 Answers 5


WD-40 can be used in the bottom part of your glass door so they won't be able to climb, sliding down, and it will be invisible. WD-40 is waterproof, so it will be effective as a barrier even after a season of rain. Vaseline can also be used for the same purpose, but it's messy and needs replacing often.

Another tip: keep them from crossing anywhere using a copper tape, the snails feel a kind of shock touching it, so it will keep them away. https://www.youtube.com/watch?v=osZXETdJ4mw

  • Paulo, welcome! I think this answer would benefit from an edit: How should one use the WD40? Spraying it all over the glass door is probably not what you meant? (Or what the housewife in me hopes...) Consider taking the tour and browsing our help center to learn more about the site and the SE system in general as well. Again: Welcome!
    – Stephie
    Commented Jun 17, 2016 at 18:47
  • I have tried the WD40, but this also keeps my windows greased up, which hinders visibility... The coppertape doesn't work on slugs sadly enough... Commented Jun 20, 2016 at 14:53
  • @RichardBernards If you attach the copper tape (doesn't have to be copper) perpendicularly to the wall, are the slugs still able to cross it? Let's say, you use a tape 2-3 times wider than shown on the video and bend it in the middle at a right angle?
    – Headcrab
    Commented Nov 14, 2018 at 1:37
  1. petroleum jelly, apply it along the edges of glass with sponge/microfiber cloth.
  2. put some sand/sawdust along the path on the floor/ground that they use to climb on the glass
  3. Copper Grease applied similarly to jelly will work too
  4. Copper tapes, again along the edge of the glass or as line of defense before/after sand/sawdust.
  • petroleum jelly and copper grease, just like wd40 greases up my glass windows... Thats not a viable solution for me.... The copper tape doesn't work on slugs... So I'm going to try number 2; sand on the runway; will keep you updated :p Commented Jun 20, 2016 at 14:55

There is a product for slug and snail killing, I used to live in a house where it was heavily shaded by massive oak trees, and had a real slug and snail problem, I bought a box of it at the home improvement store. If I remember it looked kind of like very small wood shavings. They LOVED it, but found their bodies everywhere the next day. It really, really works! I'm sure there are several brands out there, but it wiped out a large population in just a few nights.

  • 1
    Is the solution to keeping snails off you windows really total eradication? Commented Jun 17, 2016 at 18:21
  • 2
    And by proxy wiping out a few other animals who eat the poisoned slugs...
    – Stephie
    Commented Jun 17, 2016 at 18:43
  • The poison might be only active on snails tho, but there's a possibility its also unsafe for other species.
    – Just Do It
    Commented Jun 18, 2016 at 14:18
  • I'd like to refrain from killing them, but if all else fails, Ill try it... Commented Jun 20, 2016 at 14:51

They are coming in through the bilco door we have, I am using Sevin which does work and salt which dehydrates them. There is a ledge that you have to step over that has Sevin all over it and the edges on the upper wall of the bastiges.


Put two lines of copper tape and connect a 9 volt battery to the lines.
This means when they slide on and touch both lines they create a short circuit.

It's very effective. See here: https://youtu.be/GtqVO6jnMvw

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