I went to check on my wolves and a litter had grown up. Yay!
But then I noticed they were in a different order than before. The last member of the litter (Hare) had been moved to the front of them. I left them in the order they were originally put in which initially had them in order by ID. The original order was Evergreen, Umbra, Mushroom, Hare but now that they are adults it is Hare, Evergreen, Umbra, Mushroom. I am fairly sure I didn't reorder them as I don't think I have reordered any wolves, as other than that litter they are still in order by ID. Here is an image in case I do end up reordering my wolves.
I actually find this quite funny, as I imagined Hare as a bit of a prankster as a pup, so it is quite fitting that Hare would decide to move locations and surprise me.