This is Ferdie escaping - in this case, from a wire fence surrounding an earth-moving vehicle that he just wanted to get to, for no good reason. (That's Kenzie watching him). I was reminded of Charlie's behaviour in the last year or so of her life when she was very keen on getting under a fence that was running on the west side of the creek - she was desperate to get under the fence, then she had no idea what to do or how to get back.
Ferdie always likes to escape. It's a real worry, actually.