I think I’ve decided that sibling rivalry is one of life’s greatest little mysteries. After all, what on earth would possess a seemingly normal child to walk past another seemingly normal child and clock him on the head for no apparent reason?

Naturally I’ve made inquiries, but what the responses lack in reason they make up for with originality. Generally, their responses are as creative as “because he’s so annoying” or “he did it first,” or my all-time favorite, “because I love him.”

Makes no sense to me, but then I’m still trying to recover from the fight that we shall forever remember as “the day they accidentally clocked me in the jaw.”

I won’t tell you how I reacted, but I will tell you this — it cost me my Mother of the Month badge.

Experts will tell you that when siblings fight among themselves, the parents are to blame. Perhaps Mother compared little Jimmy to little Susie, and little Susie retaliated by bonking little Jimmy upside the head with her plastic play purse.

What do the experts know? Why blame the parents? You show me a group of kids who get along and I’ll show you a family on Prozac.

On more than one occasion I received the evil eye from patrons at family restaurants. I’ve been scrutinized in super centers for children who smacked, jabbed and poked their sibling in the eye. And far too often I’ve endured the proverbial “tsk, tsk” from people who’ve never had children but know for certain that if they did have children, they’d never behave like mine.

The hardest combination in the world is children and places where silence is expected. No matter how much control one thinks they have over their offspring, it’s simply better not to tempt the powers that be. All things considered, I think I’ve been wise to keep my little dears away from libraries, weddings, yoga classes, and any and all beatnik poetry readings.

However, I simply cannot avoid church, and I must say, church is the worst. You should know that my children’s actions cannot be deterred by discipline, time-outs or pinching. Nor can a punch/scream combo be prevented by a long and thought-out lecture titled “Does Everyone Recall How to Behave in the House of God?”

I’ve explained to my little dears that there is to be no name-calling once we are inside the cathedral. I’ve made it known that wrestling will not be tolerated, punching is prohibited and under no circumstances is anyone allowed to shove, even if a sibling asks for it.

Still, my little angels continue to clobber each other during the homily and shriek out loud in the middle of The Lord’s Prayer. During moments of reverence when God’s spirit could be felt by those who seek Him, one of the little dickens will throw a kidney punch and knock his brother darn near into next month.

Talk about ruining the moment.

I’ve longed to worship in a pew all to myself, far removed from the children and their distractions. I’d like to have a direct view of the altar, a seat close to a speaker, and if all was right, a good shade of lipstick that totally matched my new cute purse. Instead, Sunday after Sunday, I am forced into a crowded parent/child seating arrangement.

Then something miraculous happened. A Sunday went by when the children behaved. Then another. “Could we be over the hump?” I asked my husband on the way out the door.

“Quiet,” he answered with fear, “you’re bound to jinx us.”

Nearly a month went by without a chapel dispute. Service after service, our little cherubs marched into the pew without touching each other. They knelt at the right time, prayed on cue, and although it seemed too good to be true, services passed without an incident.

Right up until last Sunday. Turns out that instead of turning over new leaves, they were saving up for one big pow-wow. Trust me when I say it was hard not to verbalize hostilities. I whispered, “Stop it,” more than once. I shot a glare when it was necessary, rearranged two of the boys in a moment of frustration, and when I’d had enough, I bent down and said in a tone that surely sounded like the devil himself, “Can’t you heathens see that Mommy is trying to worship?”

They can try explaining sibling rivalry all that they want to. They can blame it on the parents, blame it on bad genes, blame it on family dynamics or the Geneva Conventions.

But I know what the real cause is: Sibling rivalry comes from having more than one kid.

Lori Clinch is the mother of four sons and the author of the book “Are We There Yet?” Her e-mail address is clinch@atcjet.net.