Yeah, my guys do it too. Just paired a younger guy with a slightly older boar. Older boar does the rumbling and the little guy loves to run full-speed through all the tunnels.
My girls (have 4 pups and their mom) will all start spazzing out at the same time and then run full speed through all their tunnels and then loop back around almost like a figure-8, sometimes all will follow each other, looking like a gp train, then everyone starts "popcorning." Looks silly seeing their mom trying to keep up with the smaller girls. Really reminds of what cats do when they have a nightly freak-out and run around in a similar manner.
For what it's worth, you can put their tunnels/stuff etc. either IN the route they are taking or out of the route. I have a bunch of 3" ABS (the black piping, white can have added chemicals) drain pipe pieces (45, 90 degree ends, T sections, etc. that can all slip-fit each other) and constantly rearrange the pieces to form new/different shapes like "S" or long straight sections (they seem to love this, and will immediately go through the new sections any time I make shapes; made a "C" before with a small gap so they can enter/exit, and all of them would shuffle in then constantly go in a circle within the piping which was funny to see; as soon as they exit they see the opening for the other side of the "C" so it's like an endless cycle) "U" bends, etc. and try to put them against the walls at each end. When they do their runs, they'll go through each section in their path, which isn't cluttering the center area of the cage. They rarely move anything. If talking LARGE adults, 4" piping is better suited.
Might be noisy, but for the 5 minutes or so they are doing it, they are happy
