It's an Easter weekend thing (Uttoxeter races being the main draw for them to the area, I think?), although there was a day of note last Scarefest where they randomly turned up. I remember being on Enterprise that afternoon/evening, and having a whale of a time with them!
In my experience of them (as an operator working there, and as a fellow guest), it really is just a cultural thing. They appear to start fights, but generally
only with each other. (I say 'generally' because I know people get caught in the crossfire too). A lot of them really remind me of unruly children! I always found taking a very firm 'no sh*t' attitude with them - but with a grin on my face! - always seemed to work with them, if they gave me banter, I'd give it them back, and as long as I stayed friendly at the same time, I never got accused of racism or discrimination or anything. I would be like a very firm mother, a lot of them seem to just need some discipline in their life! They seemed to ask stupid questions just for the sake of asking stupid questions, and demanding the simplest things being explained to them, and I wouldn't really entertain that. Hard work, but I guess I was pretty lucky in that I can't remember ever having a serious problem with them. I remember getting into an argument with one traveller girl for queue-jumping in the Th13teen queue, and barging right past me (I was a guest that day), and it really doing a fat lot of good.
I think I've just been very lucky, but they've always been more a source of amusement for me more than irritation - I have heard many stories of them causing an absolute nightmare though. I think generally if they think they can run circles round you, they will try.