I recently was letting the queen loose from my NICOT queen raising box. Saw her come out and proceed to crawl around on the frame. As I was placing it back in the hive, I accidently bumped it pretty hard on the side of the hive. A few bees buzzed loose from the frame but not alot really. Came back 2-3 days later to pull the NICOT frame or larvae out and looked for the queen. Couldn't find her. Went this way for a week. No queen and no new eggs. Figured I might have crushed her by accident when I bumped the frame. Odd thing, though, they weren't making any queen cells.
Then it hit me yesterday as I put feed on the hive and looked for her one more time. Maybe she was under the screen bottom board and they can "smell" her so they're not making queen cells. I got down on the ground and shimmied under and there she was right in the middle! I crawled out to get my clips to catch her. By then she had made her way into the edge with a crowd of other bees and I can't really see in there nor get my clips in. The video attached is me using my Iphone to look up in that small area and see where she was. I could see the screen and see her but I could not see up in there without the video. I eventually stuck my hive tool in there and lightly broke up the group to get her to move out. She did, I caught her and dropped her off on the front landing board.
This video was originally intended for me to be able to see where the queen was and I'd be able show my father what I had seen that day. I was 5 when he started taking me to his hives and I worked him along side of him for years. I'm 45 now and been keeping bees on my own since my mid 20's. You can hear my little tribute to him. He's been a great teacher.

So, lesson for all of us, especially newbees...if you can't find the queen and you have SBB, never rule out under the SBB!