Not that I really mind a whole lot, as it's wearing me out trying to ensure that they all get out as much as they need and want, preferably in some kind of "fair" way. Four is just too many to bring out for long walks every day, so it's usually one for a long walk and a couple of the others together for a shorter time (which is only natural as they don't find it as much fun and all want to go their own way -- but it's still some sort of interesting).
Today Rustan acted normally, so I guess him wanting to stay in was the same reason I didn't feel very well; Possibly the flu for both of us, and now we're well.