We were sitting in the garden with a friend the other day, idling away an afternoon.

"Why have you got a cat flap in your spare room window?" he asked.

"Why haven't you got one in your back door like normal people have?"

"Ah well, that's because the dog chases the cats and kept getting his head stuck in the cat flap when we had one in the back door," we explained, "plus he kept eating all their food.

"When we got new windows and doors fitted, we decided it was easier for the cats to get in and out of the house by the spare room window.

"They are fed their meals up there as well so they can eat in peace.

"The dog is not allowed upstairs."

"I see," said our friend. "But why is the cat flap so high up in the window. Don't the cats have problems getting through it?"

"Well, yes it is," we explained, "but that's because the builder measured it wrong.

"It should have been two inches up from the bottom of the window and ten inches away from the side, instead of two inches away from the side and ten inches up from the bottom.

"However, it cost a fortune to get a cat flap fitted into a double glazed window and we couldn't afford to get it changed. The cats manage, although the fat one has more difficulty than the thin one because the cat flap itself is a bit small for her."

"I see," said our friend, as Casper the fat cat appeared, waddling along the wall.

With a huge leap, she managed to jump on to the bathroom roof, which shuddered under her weight. Another jump took her on to the spare room window ledge.

She looked around to see if any other cats were watching her then launched herself towards the cat flap.

Her head and the front part of her body disappeared through the cat flap, leaving her large belly and back legs dangling behind.

She scrabbled futilely against the glass for at least two minutes before finally managing to heave the rest of her through the hole.

After a quick look back through the window to check no other felines had witnessed her undignified entry into the house, she disappeared in search of food.

"Mind you," we said, "she must have lost about two kilos since we had that cat flap installed. The extra exercise is doing her good."

"I see," said our friend, "and why is your other cat lying on the edge of the pond peering into the water?"

"Ah, well that's because she's after the fish. She knows she's not allowed to try to catch them but she does.

"Anyway, we think she's caught them all now because we haven't seen any for days."

Just then, the dog ran out into the garden and spotted the cat.

He gave chase, she swiped him across the nose with a paw before vanishing effortlessly over the wall, leaving the dog half in and half out of the pond.

"I like sitting in your garden," said our friend "There's always so much going on."