I first noticed it when Mouth and Tail were in the same room. It would often make sense that they were both facing the same way, because they were waiting for me to dish up their dinner or wiggle a toy.
But then I started to realise that they are nearly ALWAYS pointing in the same direction.
Sometimes they will be hunched up.
Sometimes they will just be sitting there.
The 'centre of gravity'
Sometimes they will be splatting about and generally looking untidy.
My boyfriend and I like to think that they are tapping into mysterious invisible forces. Maybe they are acting as feline compasses or weathervanes of some sort.
But it is more likely that Mouth wants to do whatever Tail is doing.
He is a very impressionable animal.