Yes, foxes seem quite clever at sqeezing through small spaces – cats and hogs. too! It’s quite amazing seeing the small spaces cats sometimes manage to squeeze into.
Yes, the male hogs can be quite intolerant of each other. They don’t really like having other male hogs in their personal space. One of the side effects of feeding is that we ‘encourage’ the hogs into closer proximity to each other than perhaps they might normally be, hence there is quite a lot of biffing, rolling up and shoving in those areas. It seems fairly harmless even though it initially looks quite alarming – they have all those spines to cushion them a bit.