This morning my dog came home clutching a dead rat in his mouth.

My nine-year-old daughter and I ran and hid in the bathroom.

My five-year-old son wanted to accompany our dog and hunt more rats.

I attribute his zeal to testosterone.

Testosterone, that chemical that I misunderstood --

I thought: Stereotypes are culturally learned and can be unlearned.

I wouldn't give my son a gun - - too boyish, too violent. So he made guns out of everything he touched: forks, knives, Legos, even dolls.

The first time my three-year-old daughter had a friend over it was so quiet, I rushed upstairs, sure the two of them had fallen out of the window.

I ran into her room, breathless. They were playing on the floor quietly, arranging her dolls on the pillows.

My son throws things out the window, writes on the walls, throws the toilet paper in the toilet, takes our silver and digs with it.

Give boys a parachute and they will jump from the window and fall flat on their faces. Girls will make themselves a wedding gown and veil. You can depend on it.

And testosterone breeds more testosterone. The more a boy takes risks, the more testosterone that is produced and so on and so on.

So boys are more aggressive, more likely to take physical risks, more likely to invade a foreign country, especially if that government is headed by a short man with no fashion sense.

But it all depends on how you define risk.

Once a girl is a woman there are risks she takes that men can never manage.

For example: going blonde.

My own mother spent three years on the telephone with me discussing going blonde. My mother is a brunette and going blonde would mean that the gray in her hair wouldn't show as quickly. But would it match her skin tone?

Another example: Find me a man who will reveal the insult he received on the express line at the grocery store when he was publicly humiliated for having more than ten items.

Find me a man who will risk borrowing a personal hygiene product from a stranger in a public bathroom.

But then comes a day when the band plays a different tune.

Married men see their testosterone levels decline.

That's when they start talking about their hair (should they dye their beard?), their shopping (Slim Jims on sale) and their cleaning…(the hub caps needs to be scrubbed.)

Just when women want to get in the car and drive from Massapequa to Alaska via the Bering Strait, men join the association of the "Men Who Stay at Home."

Men stop hunting rats; they stop digging with forks.

They'll go to the mall for a good sale on Odor Eaters, but then they want home again.

You know they're home because every light is turned off.

They see by the glow of the tube.

Okay, they're still watching more than one channel at a time.

But their biggest risk is being late to the early bird special.

That's when you need to give him a parachute and tell him the two of you are going to jump together, holding hands.

That ought to get a rise out of his testosterone.