This:

started to happen when we moved some of the boys to the lower bedrooms. The vibration of them coming up and down the stairs make each picture shift out of place, and yes, some of them fall down the steps!

Any ideas for how to hang them in a way that will keep them from shifting? At this point, I’m thinking Gorilla Glue, but I’m not sure Paul would be O.K. with that idea, LOL!