It has been an unexpected response from us busy working mothers, for we believed the process of emptying the nest would elicit the merest chirps of protest from us. After all, we reasoned, how could it not be wonderful to have one less phone to answer, one less kid to hassle. The demands of juggling home, jobs and children are such that who wouldn't welcome a little lightening of the load?

But alas, one vibrant woman for whom the departure of her last son for college ended 34 years of active mothering spoke for many of us when she underwent an unexpected turnabout. She had looked forward to missing the sound of her son's voice demanding to know the evening's menu. What a surprise when, days after he had climbed into his car and driven off to California, she was confessing with confusion and pique to having "been in the dumps ever since he left."

My own stint at mothering is little more than half as long as hers, and the nest is still only two-thirds empty. And, truth to tell, there are numerous advantages to having two fewer kids around.

There's more time to turn the microscope that had been shared by the other two on to the one who'd managed to remain in pleasant semi-obscurity during all those years when my attention had to be divided three ways. The last kid at home tolerates the unaccustomed attention because the tradeoffs are formidable. She no longer has to wage mortal warfare with her older sisters every time she wants to use the car, and she can therefore make more frequent escapes from the microscope.

But there is now no doubt that, in ways I didn't know how to anticipate, each robin that flies away leaves a little hole.

And each hole is a little different because each offspring naturally brought her own style, rhythm and unique level of energy to the household.

My high-energy, on-the-go kid left a calmer kitchen upon her departure, but her absence was not always felt as acutely because she always was bustling around town in the first place.

On the other hand, my quieter, more circumspect kid rippled the air less around the living room but always could be counted on to show up for dinner.

The other variable was the unpredictability of how the kids would react to college life, which is partly a function of personality and partly a function of what kind of colleges they picked.

One of my children went to a medium-large college from a small high school and eased the transition by transforming the telephone cord into an umbilical cord. Happily, I sometimes feel she has hardly left at all.

The other freshman slipped into college like a manicured hand fits into a kid glove and forgets even to make the requisite once-a-week phone call.

When she observed the freshman protocol that requires not turning back for a final wave before walking dramatically into the dormitory, I should have known. There is a very legitimate school of thought that holds that at the price of colleges today, few parents have enough time on their hands to miss their children, what with finding extra work and juggling shrunken incomes. I fully share the terror and the poverty. But in moments when I least expect it, the September blues creep up.

I have read all the articles about "transitions" and "passages" and fully believe my friends who say about departing children: "When they are free, I am free."

That time and feeling will arrive any day now, and I've already half arrived at that ecstasy some of my friends describe.

But that state of mind emanates from wisdom and rational thinking. That mindset hovers in the highest cerebral range that reminds us to have pride in our children's achievements, in their self-sufficiency, in a job well done and other euphemistic claptrap.

Such sobriety and mental poise must come with time. As another friend puts it, "You must give things time to happen."

So give us busy working mothers a little time to mindlessly mourn our chickens who have just flown the coop. So far one less stereo to turn down wasn't all it was cracked up to be. And I've just given September to the blues.