A popular and simple cat game which archaeologists have found is as old as, well, wet cement. It consists of finding some wet cement and then running through it. There are degrees of skill, of course. Most marks are scored by running through cement which, while still being wet enough to take a pretty pattern of paw marks, is too far set for the builder to smooth them out.

This is similar to Wet Cement, only, er, not quite.

Offside is a cat game similar to Zen archery, in that it is not what is actually done but the style in which it is achieved that really matters. It consists simply of persistently being on the wrong side of

a door, and goes on for as long as human tolerance will stand and then a bit longer. A straightforward little game, only marginally more complex than the old favourite, Staring at the fridge.

However, there are degrees of complexity, and a skilled player of Offside will naturally choose locations which, while preternaturally difficult for humans to get to, will be soup and nuts for the cat to get away from.

The Locked Gerbil Mystery is a case in point.

Neighbour went away for holiday, leaving complex instructions re watering of garden, etc, but not to worry about the pullulating colony of gerbils in the dining room because distant relative Mrs Thing would drop in every day, or two to keep an eye on them.

Night comes, but not accompanied by Real cat. Familiar midnight performance, standing outside back door banging plate with spoon and calling out cat's name in squeaky voice, you know how you do, in tones that you hope will attract cat while not waking neighbours. Fancy takes hold, fears of lorries, foxes, traps float across mind.

Answer rises with dreadful inevitability, like boiling milk. Take torch, put on dressing gown, pad through dewy grass to picture-window of neighbour's house. Cat is sitting dribbling on dining table, watching vibrating gerbil colony, which is going mad. Treadmills are squeaking frantically in the night.

Mrs Thing must have been and Real cat, always on the look out for new experiences, must have wandered into the house while the door was open.

Do what any Real cat owner does in these circumstances, but cat takes no notice of shouts and threats. Run around house looking for open window, but all has been sealed tight against burglars, ie, self.

Run back home. Wasn't listening properly to instructions, can't remember who Mrs Thing really is or where she lives. Also, how long is a day or two? Gerbils seem to live indefinitely in Spaceship Gerbil, with huge food hopper and nothing to do but make more gerbils. Whereas cat eats with knife, fork and hammer and has hair-trigger appetite. How long can it last? How long can it last on gerbil?

Run back again, try garage door, miraculously been left open, bang clong thud in the misty dawn, Neighbourhood Watchers probably already have digit poised to press the third 9, police will arrive deedabdeedah, pull the other one, chummy, it's got bells on, neighbours summoned from hotel bed in Majorca, may or may not corroborate story, will have crime record, finally, shunned in street, We Are All Guilty…

Still door from garage into house itself. Locked. Wonder if situation justifies breaking in but neighbours away for fortnight, can't leave house with broken door, will have to get carpenter, etc, in, and he won't be able to come along for probably three weeks. Look under door. See cat paws. Cat has turned up to watch entertainment. Peer through keyhole, all dark, key still in there…

Sudden flashback. Eagle comic, c. 1958. Tips for Boys No. 5: Beating the Burglar. Apparently miscreants push newspaper under door, twiddle key in lock with special key twiddler, key drops down onto paper, paper pulled back under door.

Home again, grab paper, tweezers, three-in-one oil, run back, twiddle, twiddle, key drops down, pull paper, there is key. Unbelievable but true.

Unlock door. Cat no longer visible. Run from room to room. Thousands of frightened eyes stare from tower tenement block that is gerbil colony, even sex isn't so interesting as watching damp, crazed, dressing-gown wearer charging around room. Search under beds. Look out of window, see Real cat strolling down drive.

Neighbour had turned water off before going on holiday. This had meant lifting floorboard in washroom. This had left easy access to huge draughty space under bungalow, with dozens of entry holes for inquisitive cats. Slam board down, stamp heavily, break tap…

Another old favourite among cat games is:

Doesn't sound much like a game, but the most important rule about Being Good is that the cat should be good in such a way as to cause maximum trouble to its owner who can't however give it a thump because it is manifestly Being Good. We had a cat who would, very occasionally, catch some small, inoffensive and squeaky creature and leave it on the scraper mat outside the door. You know—those flat scrapers that are rather like a chip slicer, with lots of little blades sticking up? And, of course, first thing in the morning you don't look down as you step out… This might, of course, be a real cat's way of food preparation. But we knew, and it knew, that in reality it was Being Good.

All cats are now Schrodinger cats. Once you understand that, the whole cat business falls into place.

The original Schrodinger cats were the offspring of an infamous quantum mechanics experiment of the 1930s (or possibly they weren't the original ones. Possibly there were no original ones.)

Everyone's heard of Erwin Schrodinger's famous thought experiment. You put a cat in a box with a bottle of poison, which many people would suggest is about as far as you need go. Then you add a little bottle-smashing mechanism which may—or may not–smash the bottle; it all depends on random nuclear thingummies being given off by some radioactive material. This is also in the box. It is a large box. Now, according to quantum theory, the cat in the box is both a wave and a particle… hang on, no. What it is, because of all these quantums, is in a state of not actually being either alive or dead,9 but both and neither at the same time, until the observer lifts the lid and, by the act of observation, sort of fixes the cat in space/time etc. He's either looking at a candidate for the sad patch, or a spitting ball of mildly-radioactive hatred with bits of glass in it. The weird part about it is that, before the lid is lifted, not only the cat's future but also its immediate past are both undecided. It might have had been dead for five minutes, for example.

That's the story that got into the textbooks, anyway.

If you can believe it. It's like the one about one twin staying here and the other going off to Sirius at the speed of light and coming back and finding his brother is now a grandfather running a huge vegetable wholesale operation in Bradford. How does anyone know? Has anyone met them? What was it like on Sirius, anyway?