And I forgot to add that some people add a few drops of liquid dish soap to the vinegar, but I didnt do that. Just leave it sit there and let the fun begin! I changed the vinegar about once a month or when I felt the numbers started to taper off and they needed a fresh batch of enticement. You will marvel at the growing number trapped inside. You will be delightfully entertained as the numbers dwindle and return to defcon zero. It took me three months to conquer and defeat them. Easy peasy.
Oh, and you might want to spray a little bit of either bleach or rubbing alcohol at your sink drain openings each night before you go to bed. They like to hide and party in there at night. And breed. And breed.
This summer, I plan to keep a jar out at all times near the trash can (even tho I empty it daily), near any rising bread dough, and near my wheatgrass and sprouts (grown in the kitchen until I get my greenhouse). Vinegar Victory!