Running around and chasing one another is a favored pastime of kids — who don't need an excuse to do it.
Of course, ferrets don't need an excuse either, especially when there's a plastic tube involved.
These two ferrets love running after one other through this loosely knotted length of tubing. Sometimes there's a bit of confusion — how do you back up inside the tube? where's the end of the tube? (poor white ferret wants to know) — but they always find a way.