An L.A. couple has found a way to profit from something that most people don? want to think about: the common head louse.

Despised by most human beings, the bug? mere presence causes children to be sent home from school immediately and their parents recoil in shame.

But if a louse is unlucky enough to infest a young head in Los Angeles County, it may have to deal with Rona and Mark Thaler.

Two years ago the couple started a mom-and-pop company called Nitwitty to exterminate the pests ?one head at a time. Operating out of their Echo Park home, the pair makes house calls only lightly armed, with comb in hand.

?t? really an old-fashioned nitpicking,?said Rona, who provides the elbow grease while her husband takes care of transportation.

The visits last one to three hours, during which Rona carefully combs out the lice using special oils that make them sluggish. The cost is $150 to $300, depending on the number of infested heads, and includes a follow-up visit to make sure all scalps are louse free.

?ost schools have zero tolerance,?said Mark, who conceived the business based on his childhood experiences with his mother, a retired Los Angeles Unified School District administrator who became the ?ice expert?at his school.

?he really knew what she was doing in that area,?he recalled.

After initially sinking $10,000 of their savings into advertising and promotions, the Thalers broke even within months. Today, they gross anywhere from zero to $3,000 a week, depending on the time of year.

?ometimes it? a madhouse,?said Mark, adding that the best season for louse hunting is in the fall, when school opens.

Most customers learn of Nitwitty by word of mouth or from its Web site.

One of them was the South Pasadena mother of an 8-year-old who declined to give her name.

? didn? even want to see them,?she said of the vermin found lurking in her son? hair. ?hen you look at them close,?she added, ?hey?e just gross.?p>