I thought it may have been the sugar that they were attracted to in the beer, but the yeast makes more sense. Now I can stop wasting good (or even bad) beer for my slugs!
Would love to see a video on cabbage worms / moths. I'm planning on doing one shortly as that is currently my #1 battle in the garden...grrrr.
Moths are attracted to Sugar so use molasses. Thankfully I haven't had a problem with them this year but I will do a video if they appear in the future
Lucky you — I'm being infested :o