TS gave me a smack with the clue bat after I posted a reference to her work clearing up our earwig problem and didn't remember to post the recipe she is using. I consider myself clued :) , and here's the recipe...
1 cup of water
1 tablespoon of vegetable oil
1 tablespoon of honey (we've seen another recipe using molasses but haven't tried it.)
1 teaspoon 0f dry yeast
We are using both the bottoms from a few pots (very similar to a plastic saucer) and traps from Stokes Seeds (www.stokeseeds.com) where animals have access.