I found I had to spray balsamic vinegar on the traps or the flies would not go onto the board. There is already a faint smell on the boards so they are baited but the fruit flies I was dealing with were not attracted to the bait. I may have had too high an expectation of the glueboards but found that 1/3 to 1/2 of the flies went onto the boards and the rest had to be manually killed. The company mailed them out very quickly and their service was good. I did not approach them about a refund for the unused boards because I think they will help with the problem we seem to have at the end of every Summer.