Cats are strange creatures. Many seem to find themselves odd modes of unpaid — but deadly serious — employment. Maru inspects boxes with great thoroughness and Tom Cox's cat Janet (a he, not a she, by the way) collects retro plastic wrappers from a nearby lake for a living. One of our cats has also revealed her occupation recently.
When we got our cats, the previous owner told us that Bella liked to drink from the tap. This took some time to manifest itself, but after a few weeks, she would hop up onto the cistern in the bathroom and position herself near the tap, waiting for us to turn it on. You have to select just the right flow rate though, or she looks at you with that classic disappointed feline gaze which implies, "Oh, you just can't get the staff nowadays."
A short while after Bella started drinking from our taps, Bianca started her very important job: Advanced Basin Surveillance. If you have closed the bathroom door to get a bit of privacy, then open it, Bianca will come rushing in, and leap immediately on to the cistern. If she had access to a blue flashing light, I'm sure she would use it, because she shows Emergency Services levels of urgency. She then crouches down and watches the basin from close range with an intensity and focus that would shame many humans. She does this for very long periods, only changing position when a drop of water in the basin makes a break for the plughole, and then she's right on the case. It's hilarious to watch.
Between the two cats, it's actually quite hard to have the bathroom to yourself, and I've frequently found myself sharing a very small bathroom with two cats perched on the cistern or trying to walk around the edge of the basin.