Strangest burglary ever

It’s not really a complaint, as nothing was stolen. The Parents’ house was broken into and every room in the house was gone through, but from as close as we can tell nothing was stolen. My laptop was left in the room, there was a €50 note in my mother’s purse, none of the jewelry was stolen and, luckily of all, my father’s shotgun was still where he had left it. I’m convinced that the gun needs to be locked up, but as for the rest of the problems, it is really surreal. They had time to look through practically everything, but seemed to not take anything.
On the other hand they may have been looking for something specific, the question is what?