A behavioral question that has puzzled humankind for much of recorded history — along with “Is there intelligent life on Earth?” and “Why is there so much whining in the workplace?” and “How do I stop my spouse from snoring?” is this: “Why do dogs go crazy over the mailman?” (Not to mention the UPS delivery person and the FedEx guy.)

This is a more urgent issue than you might think, especially since a recent report by the U.S. Postal Service said the number of carriers bitten by dogs increased to 5,767 last year, up from 5,581, with Los Angeles having the most attacks at 74, followed by Houston at 62.

According to canine historians, dogs and mailmen have had troubled relations at least since 1775, when Ben Franklin was appointed postmaster general. Shortly thereafter, the first reported bite of a mail carrier occurred somewhere in the Ozarks.

Even though the vast majority of dogs don’t bite, they still freak out when they spot postal carriers. I’ve witnessed it firsthand. It’s like canine obsessive-compulsive behavior.

Every day at approximately 12:54 p.m., our dog Bella, who is part Maltese and part Lhasa Apso — which means she was bred to bark — climbs on the sofa to do neighborhood surveillance. She looks out the living room window, which offers a perfect view of our mailbox, and glances suspiciously up and down the street. Then, she begins to emit a low growl from somewhere in her doggie vocal cords that sounds like a tractor-trailer diesel engine warming up.

She obviously hears something that I can’t, largely because a) I’m not a dog and b) I developed tinnitus back in the ’70s during a Buddy Miles or BB King concert. I can’t remember who it was. Your memory is the second thing to go ... after your hearing.

Bella can distinguish the mail truck from every other vehicle that drives by. Even before it comes into sight, she knows that little white van is putt-putting up the street, one mailbox at a time, so she jumps on the top of the couch and starts to howl like a miniature Hound of the Baskervilles.

Suddenly, the entire street erupts in a paroxysm of ferocious barking, which could be more appropriately described as ferocious yapping because they’re all lap dogs, who sound like the cast of Real Housewives of New Jersey during a brawl. For the neighborhood dogs, this is the high point of their day, more exhilarating than pooping on someone else’s lawn.

The barking spreads like a measles epidemic from one house to the next. What canine instinct drives them all insane at the same time? Are they telepathic? Do they communicate by doggie text-messaging? I stopped trying to figure it out. Maybe our mailman knows.

When Bella sees him, she jumps off the couch, her teeth bared and her tongue wagging, and runs from room to room in hot pursuit of ... what?

Panting and growling, she dashes under the kitchen table, around the coffee table, up the stairs, down the stairs and onto the couch again. This hysteria frightens me. What did the mailman ever to do her?

For reasons my wife and I can’t comprehend, the mailman makes the problem worse. First, he drives down the street and then he drives back up the street and then down the street again. Is he lost? Or is he trying to harass the canine population? That’s the only logical, or illogical, explanation.

I don’t know what motivates the mailman, and I’ve often wondered why dogs act this way, so I did some research and discovered their behavior that goes back hundreds of thousands of years, even before the U.S. Postal Service began.

Jana Murphy, author of The Secret Lives of Dogs, says, “Every dog has a little watchdog in him. It’s something that dogs inherit from their ancestors, who had to defend their territories and limited food supplies from trespassers.” Now, they’re defending suburban families from delivery people. Or they what to prevent the mailman from stealing the stash of Alpo.

I suspect this gives dogs a sense of accomplishment. To their thinking, they protected their territory. Another job well done, you could say. Break out the Milk-Bone biscuits. Crack open a cold one. It’s doggie Miller time.

Contact Joe Pisani at joefpisani [at] yahoo.com.