No place demonstrates the differences between men and women better than the average family home.

For centuries women have tried to tame men into understanding what living under a roof means. But males are genetically programmed to run around waving spears in the bush.

Men have a special gene that allows them to crunch barefoot across a kitchen floor without noticing it needs sweeping. They think damp towels strewn on floors have built in homing devices that fly them back neatly folded on to bathroom rails.

They believe the only time toilets need cleaning is when people are coming over for dinner.

Even the tamest of men who have learnt to pile their dirty socks and underpants in some designated place like a corner of the bedroom or the back of the wardrobe have no idea what happens next.

They think their clothes reappear magically clean and scented with ironing aid in their drawers and cupboards. When for some reason my husband’s favourite shirt hasn’t rematerialised within a couple of days of wearing it, he’s genuinely mystified.

“Has anybody seen my shirt?” he’ll ask, as if the thing has run away like a puppy.He’s equally mystified if the shirt returns minus a button.

“I’ll fix it,” he says.

He then takes the shirt to the laundry and drapes it over the tool box, which (thanks to imaginative design in a Korean plastics factory) resembles a larger version of my sewing box.

If after a few days, the shirt remains button-less, he’ll sigh and offer to take it to a professional repairer.

“I thought you were going to fix it?” I’ll say.

“I was but I couldn’t find any buttons.”

For a moment I wonder if it’s worth asking which box he’s been looking in – the tool box or the sewing box. He does have trouble identifying things around the house. The other day when I asked him to put a dirty towel in the machine he said “Which machine?”

Most men don’t realise shirt buttons cluster like shellfish at the bottom of a sewing box. The prospect of being replaced by a professional repairer is enough to get me diving for the pearly little things.

Men have strange ideas about what needs keeping and what should be thrown out. He always puts leftover bits of pizza in the fridge, promising he’ll eat them for breakfast. The only people who seriously eat cold pizza for breakfast are 16 year old boys.

Two weeks later an evil stink wafts through the kitchen. Everything in the fridge is tainted with a sour flavour. Like Jacques Cousteau about to plunge into the deep, I put on rubber gloves and breathe deeply.

The source of the stench is on the bottom shelf lurking behind a two year old jar of feijoa jam and bottles of beer waiting for the day an entire rugby team drops by for drinks - two wedges of what look like the inner soles of decomposing running shoes. His forgotten pizza.

If only he could have applied the same theory to the plastic bottle I used to store laundry liquid. That bottle may have looked a bit messy with congealed blue goop down its sides, but it was a major environmental project.

Instead of replacing the bottle every few weeks, I refilled it with liquid from a cardboard container. While my efforts probably weren’t doing much for pine forests, they were no doubt stopping several icebergs melting and saving half a dozen whales.

The other morning I was horrified to discover the old plastic bottle was missing. After rattling through various cupboards, I realised what must have happened. He’d mistaken my precious laundry bottle for rubbish and binned it.

I’m not saying another word. A middle aged woman going on about a plastic laundry bottle could sound naggy, possibly even a touch insane.

Besides, having a spear wielding warrior around has advantages. Every now and then he becomes a fearless dispatcher of spiders, an investigator of creepy noises in the night, a remover of dead rats – and I can’t imagine how we’d survive without him

In the meantime, readers have sent in fascinating emails about household objects. According to Clive Aim of Wanganui, Velcro can be lethal after all. He says the deadly fires on Apollo One in 1967 were fuelled by Velcro astronauts had used to stop things drifting around the cabin.

As a result of last week’s column, Roz Redpath of Christchurch has been using dental floss to stop her ironing board cover wrinkling. Go Roz!