Hi Mandy.
They all seem to love that last roll in the mud before farrowing. Always come back smelling of horrible silt but they really enjoy it. I had one come back which looked like a large black (albeit with prick ears!). Got a pic somewhere - will dig it out.
I also had one who fancied a water birth. Took two hours to get her out of the pond. You can imagine what she smelled like after rolling around in all that gunk at the bottom.
Main thing was, she was happy - and had a lovely relaxed birth soon after (fortunately, back in the barn!).
A few of mine have gone bonkers in the hours before farrowing, ripping off gates, breaking through the walls of galvanised barns. A bit of a run around and a wallow and they come back, tired, relaxed, and happy.