It was 2:40 on a Tuesday.

I was in the pickup line at Ellie's school when my phone rang, and the nurse said the sentence every mother dreads in a voice that told me she'd said it a hundred times that fall: "We found live lice in Ellie's hair.

You'll need to treat her before she comes back."

Ellie is in second grade. She has hair to the middle of her back that she will not let me cut.

I did what you're probably doing right now. I drove straight to CVS with her in the back seat and stood in the aisle reading boxes.

I bought the Nix kit because it's the one everyone knows. $27 and change.

That night I followed the box exactly. Ten minutes on, timer running, rinse, then the comb. My husband held the flashlight. Ellie cried.

We found bugs, and we found little tan dots stuck to the hair near her scalp that would not come off no matter how I pulled the comb.

I stripped both girls' beds at 11 PM. I ran the sheets on hot. I put every stuffed animal in the house in trash bags in the garage.

I thought I was being thorough. I want to be honest about that, because it matters later.

Wednesday she went back to school. Thursday her sister Maddie started scratching. Thursday night: Nix again, second head, $27 again.

The box said to repeat in nine days. I put it on the calendar like a doctor's appointment.

Day 9 was a Thursday. I did the second Nix treatment on both girls the way the box said.

And when I combed Ellie out afterward, there was a live one on the comb. Moving. After two full treatments.

I did what I think most of us do at that point — I decided Nix was the problem and switched brands.

Friday I bought the new RID One & Done, the purple box that says ONE TIME, NO NIT COMBING, 10 MINUTES right on the front. $42 for one tube.

One tube does one head, so that was Ellie's, and I told myself Maddie could wait a week and we'd see.

Ten minutes, rinse, done. No combing, the box said. So I didn't comb. The tan dots were still in her hair, but the box said not to worry about them.

The next week I ordered one of those cheap lice kits from Amazon, the kind with 4,000 reviews and a $16 price, because at that point I was buying anything.

I was combing both girls every single night. I was washing sheets every other day. I had spent $112 on treatments and I don't know what on laundry, and it was going on three weeks.

The Saturday of week three, Maddie had a birthday party to go to. I called the other mom and made up a stomach bug. I sat in the car in the driveway afterward for a while.

That Monday the nurse called again. Ellie. Live lice. Again.

I asked her, and I'm not proud of my tone, what exactly I was supposed to be doing that I wasn't doing. And she said something I didn't expect.

"Honestly? Call Dave. He's the one I'd call if it were my kid."

Dave does lice removal for a living. He's been doing it for twelve years. I called him from the school parking lot.

I told him the whole thing — Nix, Nix, the $42 RID, Amazon, three weeks — and waited for him to tell me I'd combed wrong.

He asked me two questions.

"Those tan dots that won't come off the hair. Are they still there?"

Yes.

"And what have you done about the couch?"

I hadn't done anything about the couch. Why would I? Everyone knows lice can't live off a head more than a day or two.

"Right," he said. "The bugs can't. The eggs can. That's your whole problem, and it's not your fault. Nobody tells you this."

Then he explained it, and I'm going to give it to you the way he gave it to me, because it's the reason I'm writing this at all.

Nix is permethrin. The RID most of us grew up with is pyrethrin. They're cousins, and they've been the same poison for about forty years.

Forty years is a long time for a bug to get used to something.

Researchers tested lice from 48 states and found the resistance gene almost everywhere they looked.¹ That's why I could do two rounds of Nix by the book and still find a live one on the comb: most lice don't die from that poison anymore.

The cheap Amazon kit was the same chemical with a different label. I'd bought the same thing three times.

The $42 RID One & Done is different — it's ivermectin, a drug that shuts down the louse's nervous system. Dave was fair about it: it kills bugs the old stuff can't. But read the box again. One time, one head, ten minutes.

It doesn't claim to do anything about eggs, and it can't do anything about eggs that aren't on a head anymore. For four of us that's four tubes, $168, and not one word about the couch.

I'd paid $42 to treat one head and skip the combing, which turned out to be exactly backwards.

And none of it touches the eggs. Those tan dots I couldn't get off Ellie's hair are eggs, and each one is glued to the hair with a hard shell of protein. The poison can sit on that shell all day; it can't kill what's inside.

About a week later they hatch.² That's the "nine days later" on the box. It isn't a second treatment. It's a confession.

So it wasn't new lice coming back. It was the same lice, from eggs the box was never going to kill.

Here's the part that made me put the phone down for a second.

You lose 50 to 100 hairs a day. So does every person in your house.³ When someone has lice, some of those hairs have an egg glued to them, and those hairs land where your kids sit. The couch.

The car seat. The pillowcase. The headrest. The hoodie she wears three days in a row.

In lab tests, lice eggs kept off the head in a warm room hatched about 12 days later — 8 out of 10 of them.⁴ A couch cushion with a seven-year-old sitting on it is a warm room.

So I'd been treating heads. Five times. And every time, a clean, combed, exhausted kid sat back down on the same couch.

If your kids are like mine, that couch is where they live. That is where it kept coming from — that, and the eggs the shampoo never killed. Yes, kids also pick it up again at school.

But most of the time, Dave said, the ones that "come back" never left.

Dave doesn't use poison. He said you stop trying to kill something that doesn't die from poison, and you go after the glue instead.

There's a treatment built for exactly that. Step one is an enzyme that dissolves the glue holding each egg to the hair and softens the shell of the bug itself.

It's a physical thing, like sugar dissolving in water, which is why a louse can't "get used to it" the way it got used to Nix.

Step two is a blend of plant oils — clove, neem, peppermint, eucalyptus — that finishes what's left. No permethrin. After three rounds of the other stuff on a seven-year-old's scalp, that mattered to me more than I expected.

Then he said the thing I'd been doing wrong for three weeks: "You need to treat your family's heads and your environment — laundry, furniture, cars, all of it. Use a premium metal lice comb.

And I use an ultraviolet flashlight to make sure I've got every bug and every nit. Ultraviolet makes them easier to see."

The kit is called the Everything You Need Kit, from a company called LiceKiller. Dave has been using their enzyme and oil for years on other people's kids.

It's a little over $150. I'm not going to pretend I didn't wince. I almost closed the tab.

Then I did the math to figure out what these bugs had already cost me. Nix, Nix, the $42 RID, Amazon: $112. A prescription copay if I went that route: $30.

Two lice clinics I called that afternoon: $125 to $250 per child, and I'd still be doing the couch myself. A lice service that comes to your house: about $450 for the four of us.

The Everything You Need Kit treats every head in the house, plus the couch and the car and the beds, with the metal comb and the ultraviolet flashlight included. Less than one child at the clinic. Less than I'd already thrown away. Free 2-day shipping.

I ordered it Monday at 4. It was on the porch Wednesday afternoon.

Wednesday, 6 PM. The directions say to wash out any hair products or old pesticide treatment first, so both girls got a regular shampoo and a towel-dry while I read the sheet at the kitchen table.

Then Ellie sat on a stool with a towel around her shoulders and I parted her hair into small sections and worked the Nit Glue Dissolver right onto the scalp and the first couple of inches of hair, section by section, massaging it in, until her whole head was wet with it.

Shower cap on. Then Maddie, the same way. Then me. Then my husband, who swore up and down he didn't have them, sat down in a shower cap too. Four of us at the kitchen table in shower caps, and I set the timer for thirty minutes.

You don't rinse. When the timer went off I put the LiceKiller Oils on right over the top, and the directions are strict about this part: saturate every strand top to bottom, no dry spots anywhere. Caps back on for another half hour or so.

That is the half hour I used for the house. The kit comes with a Furniture Spray Concentrate and an empty sprayer bottle: fill the bottle with warm water up to the neck, pour in the whole little bottle of concentrate, shake.

I pulled every cushion off the couch and sprayed the cushions on both sides, the frame underneath and the throw pillows, and left them off to dry overnight.

I took the bottle out to the garage and did both car seats, the headrests and the seat Ellie sits in behind me.

Back inside I stripped all four beds and started a load of sheets, pillowcases and the pile of hoodies from Ellie's floor with two ounces of the Laundry Concentrate from the kit, then sprayed the mattresses and pillows before the fresh sheets went on.

Backpacks, hairbrushes, the bike helmets on the hook by the door. The whole house took about twenty minutes. I had spent three weeks not doing this.

Then the combing. Ellie bent over the bathroom sink with the towel across her shoulders, cap off, and I pulled the metal comb through in a scraping motion along the scalp, one small section at a time.

The eggs that had survived three weeks of everything I'd thrown at them came off the hair on the first pass. I wiped the comb on a paper towel and there they were, a little row of them.

A couple of bugs came out too, barely moving, which the directions warned me about: the oils don't kill them instantly, but they can't crawl and they can't breed, so you rinse them down the sink.

I actually said "oh my gosh" out loud and Ellie asked what was wrong. Nothing was wrong. For the first time in three weeks, nothing was wrong.

It's fair to say the combing still takes a while. Long hair, close to an hour for Ellie, and you keep going until the comb comes up empty and then do the whole head one more time. That's the honest part.

Then a regular shampoo, twice, to get the oil out. Maddie, me, my husband. He had them. We did every head and the whole house in one evening, and we were done by 9:30.

The directions say to check every head every night for the next week to ten days, keep washing the bedding and keep spraying the couch, because a re-infestation from your own house can happen fast. So I did.

Every night that week I went over both girls with the ultraviolet flashlight, and put the Lice Repellent from the kit on the backs of their necks before school. Nothing. Day 3, nothing. Day 7, nothing.

The nurse checked Ellie the following Monday and sent her back to class. It has been four months. I still check on Sundays because I'm that mom now, and it's still nothing.

Before I ordered, I looked them up the way you're about to. The same family has made it since 2004. More than 100,000 families have used it. Their refund rate is under one percent.

A lice-removal expert showed it working on ABC's Nightline, and a customer named Kathy made a video about it in 2008 that's still up — she sounds exactly like me on day 9.

And there's a money-back guarantee in writing on their site, next to the button. If it hadn't worked, I'd have sent it back. It worked.

If you've done Nix or RID once and you're staring at the box wondering whether to do it again, this is the part I wish someone had told me on the first Tuesday.

A louse lays about six eggs a day. Each one hatches in about a week. Every night you wait, the number of eggs in your house goes up — on heads and off them. The second box doesn't change that.

The $42 purple one doesn't either, and neither does the one from Amazon. I know because I bought all of them.

If you order before 4:45 PM Eastern (1:45 PM Pacific), the kit ships today and it's on your porch in two business days, free.

You do every head and the house that evening, the way I did, and you check every head with the ultraviolet flashlight every night for a week.

Two business days from now, this is either over or it's another week further along. That's the whole decision.

The Everything You Need Kit, sized for your family, with the ultraviolet flashlight in the box. Free 2-day FedEx. The guarantee, in writing, right next to the button.

I'm writing this because nobody told me any of it in week one, and I'd have paid $150 on that first Tuesday to skip the next three weeks.

— Jennifer

P.S. If your school has a no-nit policy, the ultraviolet flashlight in the kit is how you know she's clear before the nurse checks. I didn't have one for three weeks. I was guessing.

Editor's notes and sources

1. Gellatly KJ et al., "Expansion of the knockdown resistance frequency map for human head lice in the United States," Journal of Medical Entomology, 2016 — kdr resistance alleles found in lice sampled from 42 of 48 states, at very high frequency.

2. CDC, "About Head Lice": nits take about a week (6–9 days) to hatch on the head. cdc.gov/lice.

3. American Academy of Dermatology: it's normal to shed 50 to 100 hairs a day. aad.org.

4. Sonnberg S et al., "Ex vivo development of eggs from head lice," Open Dermatology Journal, 2010: eggs incubated off the host at 77–83°F hatched at 80.9%, with hatching beginning at a median of 12 days. Leeson HS, Parasitology, 1941: louse eggs hatch at temperatures down to about 75°F and not below. The CDC's position is that nits away from scalp temperature usually do not hatch; the studies above describe what happens in warm conditions.

Nix and RID One & Done are trademarks of their respective owners and are not affiliated with this site. Prices are what the writer paid and vary by store. Mothers Against Head Lice is a reader-supported site; Jennifer's story is presented as told to us. Individual results vary; this page is not medical advice.