I've recently tried a number of methods I read about on-line. I tried using a a square of corrugated cardboard, both with and without Fipronil poison. I found that without bait/poison in the cardboard, the beetles don't really hide out inside it. I tried splitting a couple of spots, filling with bait and covering the splits with duct tape and attaching a string to pull it out without opening the hive. It worked too well! The shbs jammed into it. The bees, aware of all the intruders chewed the daylights out of the cardboard to get at them to evict them. Luckily, either they didn't get to the poison, or didn't eat it, as I had no dead bees from it. They also pushed the cardboard out of the hive. I wouldn't recommend this method unless you use the PLASTIC cardboard like they use in signs and you use a piece big enough to prevent them pushing it out of the hive. I tried the baited plastic sandwich box, but found it to be too cumbersome to fit in the hive. I put an empty super on to house it, but found I only provided extra places for the shb to hide and didn't trap that many shb. They seem to prefer the lower corners of the hive. My best solution to date is an empty CD case. The 4 holes are the perfect size to let the shb in but not the bees. It is slim and fits nicely underneath the frames. I taped on a length of monofilament fishing line that they can't chew through and baited it with Fipronil. They ate it up! After a week in the hive it was full of the bastards and all of them were DEAD. It is easy to pull it out, empty and re-bait, and no messy oil to attract other problems like raccoons or oil-eating ants. As an added benefit, it kills ants and other pests as well. My bees are WAY less cranky with fewer shb in the hive. I tried to buy the screened botton board/oil pan on-line, but there was a glitch on the page that kept asking for info that was already there. They had no phone # or other way to buy, so I gave up.