Wow, very cool pictures.
Several species of reptiles and amphibians are known to occasionally form "mating balls"
And several species of birds are known to form predator and cold deflecting "coveys"
But I've never heard of pigs doing either of these things.
Now the two biggest boar hogs I've ever seen were beded down fairly close to each other in the mid of the night, in the middle of a huge stuble field. so it does happen. We walked within yards of them, never even knowing they were there. When we were long past them, one of the dogs must have got wind, it circled back around, and bayed. So we released the rest of the dogs. Each of the pair of hogs had a catch dog on an ear and they were spining like bulls with the dogs hangin on for dear life, they looked like a pair of helicopters.
