They're waiting even as you pack up to come back from your vacation: waiting for the footsteps, the naivete, the feast. Waiting to ruin that happy (and expensive) holiday you anticipated so long and enjoyed so much. Until you got home, that is.

Before you can even drop the first suitcase in the bedroom, you are attacked. Away from "Home, Sweet Home" for two whole weeks, and now you can't wait to get out.

"Home, Sweet Home" has turned into a House of Horrors. Is it burglars? Unexpected relatives? You wish.

Fleas. By the legful. Your white tennis socks are glitteringly alive, black flecks snapping on like tiny magnetic popcorn.

Your distress is matched only by your disbelief; the dog hasn't even been picked up at the kennel (where he had been shampooed and flea-dipped, prudent pet-owner that you are) and you'd arranged to have the cat fed outside on the porch. You scratch your ankles and head at the same time. Where did this marauding hoard come from?

If this all sounds dreadfully familiar, you aren't alone. Fleas by the millions -- billions, I suppose -- are busily hatching in warm, closed-up homes this time of year. With no pets or people to jump on, they are literally lying in wait for that opening door and the delicious naked flesh it promises.

My phone has already started ringing with requests for some ultimate flea solution. Somehow, I have the unlooked-for distinction of being the neighborhood authority on these miserable pests.

Did you know, for example, that there are more than 500 species of fleas? And that they live solely on blood? That cute expression your veterinarian uses when examining your pet's coat this time of year -- "flea dirt" -- is just a euphemism for flea excrement; those tiny black crescents are dried blood from your pet, having passed through this disgusting parasite.

On their behalf, I should say fleas are not a bane to everything; tapeworms need fleas as an intermediate host in their own life cycle. That's about as close as I can get to saying anything nice about fleas, and one more reason to hate them.

Everyone has a favorite flea remedy, which, like ways to quit smoking, is generally unproven and dubiously effective.

For example, my neighbor Roxanne swears by brewer's yeast. She puts one tablespoon of the stuff on her fuzzy old terrier's food twice a day, and in conjunction with monthly groomings at the poodle palace, she managed to keep the little boogers at bay. Of course, Twinkie doesn't go out much into the yard anymore; I think he uses a cat box.

The only other person I know who truly believes in brewer's yeast for flea control is a hip veterinarian I met in Los Angeles, who was also experimenting at the time with acupuncture and a strap-on skateboard for an overweight dachshund with a back problem. Her treatments always displayed oodles of funk, I must admit, but cures did not seem to be her forte. Nor did her reasoning regarding cause and effect. Of course, what apparently works in California does not necessarily relate to life on the rest of the planet.

The fact is, in a fair trial, brewer's yeast was proven to be thoroughly ineffective in repelling fleas from my dog.

My organic friend Jacquie has also tried brewer's yeast on her retriever, Iris. However, she claims more effectiveness in weekly saltwater dips, alternated with rosemary- and-thyme tea dips. We have corresponded several years on the subject and she still signs her letters: "Love, Jacquie, Paul, Annie (the baby), Iris and The Fleas."

Of course, there are always the old standbys. Sprays can kill adult fleas, if your pets don't go into a rabid, frothing fit at the sight of the can, as mine do. Not only do all cats hate sprays (such irony), but many dogs are terrified by the sound.

A flea collar is much neater and consequently more popular. Put it on and forget it for a few months. Unfortunately, flea collars are expensive, need replacing more often than they're supposed to and, while they do a darn good job of keeping the head and neck area flea-free, they don't seem to bother the mass of the population down by doggy's tail and groin. If they'd only come out with a flea belt. . .

There are lots of flea soaps and shampoos on the market too. They also kill adult fleas on your pet, but since the residue rinses out, you are left with a shiny-clean, pest-free pet for about half an hour until he dries out. The soaps can be irritating to your dog's skin, too, especially if you're repeating the treatment often and Fido is scratching in between. That's how those wretched "hot spots" can get started.

In my own war on fleas, I powder and dip. An exterminator friend (it pays to have friends in the right places) told me to skip the expensive commercial flea powders; plain old garden Sevin works best. Powdering of all pets occurs once a week -- barring rain and forgetfulness -- followed by a thorough brushing to get rid of the little corpses. I dip the dog once a month during flea season with a concentrated commercial dip, available at most pet shops. I dip the cats once -- in June. This is not something I recommend to the faint of heart or sinew, or to those who have never handled a panicked feline. It's not a happy scene, but it's over quickly, hit or miss.

Okay, so that's for the pets. What about the house, that ideal flea incubator with guaranteed food supply?

Fortunately, the commercial establishment is finally recognizing the gravity of our situation. It seems as though all the major pest-control companies have come out with their own brand of "room fogger," or, as I prefer, "bomb." They're going to sell like crazy. They do work -- on adult fleas. Unhappily, flea eggs are resistant to everything short of an A-bomb -- and who knows about that? Under optimum conditions, they hatch in about five days, but can remain viable for more than a year in your carpets, drapes and furniture. So you're going to have to repeat the bombings, too. This is not just a battle, it's war.

So, if you really can't part with your flea- bitten pets, and want them to lead a life that includes both the great outdoors and a place in your home, resignation and determination to fight the flea war are your most important weapons. In this case, the best defense is a good offense.

And when it all falls apart, remember my friend the exterminator. He has chemicals we nonprofessionals can't get, and he can provide that all-out attack, that blitzkrieg of insecticide that you need. He will tell you how resistant fleas are and will probably give you only a limited guarantee. Like 30 days. Last year, this flea expert saw her friend three times. In the same month.

One other possibility, of course, is vacationing at home. There are lots of fun things you can do at home. Like spraying, powdering, dipping and bombing . . .