Back to School 2026: Why School Bags and Cloakrooms Spread Head Lice and Bed Bugs

Introduction: the new school year, a great pest mixing bowl

Some dates come back unfailingly in the diaries of pest control technicians and school nurses. The first is the Monday of the new school year. The second falls about ten days later: that's when the first notes start circulating in home-school notebooks, when parents discover nits behind their child's ears, when a family calls in a panic because their child woke up with three bites lined up along their forearm.

The start of the school year is not a biological event. No insect breeds faster on 1 September. But it is a major logistical event: within a few hours, several million children bring their hair, coats, school bags and comfort blankets back into contact after eight weeks of summer dispersal across the whole of France — and sometimes beyond. Pests that live off human contact need nothing more.

Two species take particular advantage of this mixing, and families constantly confuse them: the head louse (Pediculus humanus capitis) and the bed bug (Cimex lectularius). The first is harmless, common, and has nothing to do with hygiene. The second is rare at school but formidable as soon as it crosses the threshold of a home. Confusing the two costs weeks.

Lice or bed bugs: the table that saves you three weeks of mistakes

One point deserves repeating, because everything else follows from it: lice do not jump and do not fly. They move by gripping hairs, at roughly 23 cm per minute. Transmission via hats and brushes exists but remains marginal: the reference studies cited by the French health insurance service (Ameli) and by Vidal place the vast majority of infestations in head-to-head contact — the class photo, the nursery nap, playing on the floor, the selfie between pre-teens.

The bed bug does exactly the opposite. It never lives on the body, doesn't hide in hair, and travels only in objects. A school bag resting against a neighbour's coat for six hours is a far more credible vector than the child themselves.

Head lice: what the epidemiological reality says

There is no mandatory surveillance of head lice in France: scalp pediculosis is not a notifiable disease. The available estimates, relayed notably by Ameli and the French health ministry, place prevalence among children aged 3 to 11 within a wide range — several percent as an annual average, with classroom peaks that can exceed 20 to 30% of pupils in the weeks following the return to school.

Three false beliefs cost families dearly:

"Lice are a hygiene problem." False, and debunked long ago. Lice attach just as readily to clean hair as to dirty hair. Daily shampooing protects against nothing. This belief has a real cost: it produces shame, therefore silence, therefore entire classes reinfested because nobody reports anything.

"The child must be kept out of school." No. Pediculosis justifies no exclusion from school in France. A treated child can return to class the same day. The only duty is to inform the school, so that other families can treat simultaneously.

"One application of product is enough." This is the most common mistake and the main cause of failure. No product available in France kills 100% of nits. The cycle runs as follows: a nit hatches in 7 to 10 days, and the young louse starts laying eggs in 9 to 12 days. A second treatment 7 to 9 days after the first is therefore essential, within the window when hatching has occurred but no new egg-laying is yet possible.

The protocol that actually works

1. Confirm before treating. An itchy scalp is not proof. You need to see a live louse or live nits, glued less than a centimetre from the scalp. Further along the hair shaft, these are empty shells — remnants of an infestation that is already over. An examination in daylight with a metal lice comb, on wet, detangled hair, remains the most reliable detection method, far superior to inspection with the naked eye.
2. Choose a treatment with a physical mode of action. Products based on dimeticone (silicone) mechanically suffocate the insect by blocking its breathing spiracles. Unlike classic neurotoxic insecticides (pyrethrins, malathion), they generate no resistance — a now central point, given that pyrethroid resistance is documented in several European countries. This is today the recommended first-line option for children.
3. Respect the contact time. Too many families rinse after ten minutes. Read the leaflet: depending on the formulation, it takes anywhere from 15 minutes to 8 hours.
4. Comb, then comb again. Systematic combing every 2 to 3 days for two weeks, strand by strand, on damp hair coated with conditioner, mechanically removes a significant share of the population. It is tedious, and it is what makes the difference.
5. Treat the whole infested household on the same day. Treating the child alone and leaving an asymptomatic sibling carrier guarantees a relapse.
6. Don't disinfect the house. A louse dies within 24 to 48 hours away from the human head. Washing bed linen and hats used in the previous 48 hours at 60 °C is amply sufficient. Foggers and room sprays are useless here and needlessly expose children.

Wet combing is the only method that acts as both diagnosis and treatment. It is also the only one to which no resistance is possible.

Bed bugs: the school bag scenario

Now for the pest that shows no mercy. Bed bugs don't settle into a school the way they settle into a home: classrooms lack what is vital to them, namely a host that stays still for several hours on end, at night, always in the same place. School premises are therefore rarely infestation sites as such.

They are, however, excellent transport hubs. The mechanism is always the same:

• A home in the local area is infested.
• A bug, or more often an egg clinging to a seam, leaves in a child's school bag or coat.
• That bag spends the day pressed against fifteen others on a coat rack or in a locker.
• In the evening, another child brings the bag home and puts it on their bed, like every child in the world.

The high-risk moments are clearly identifiable in the school calendar: the return to school, with pupils arriving from everywhere; nursery nap rooms, where bedding and comfort blankets stay on site; school trips and outdoor education weeks, spent sleeping in group accommodation with rapid turnover; and finally boarding schools.

The right back-to-school habits at home

They are simple and cost very little:

• Never put the school bag on the bed. Nor on the sofa. A dedicated spot near the entrance — a stool, a tiled floor, a bag stand — is enough. This is the highest-return measure on the whole list.
• Choose bags with smooth surfaces, without a multitude of seams, gusseted pockets and Velcro. Smooth surfaces offer few hiding places.
• Empty and inspect the school bag on Friday evening. Seams, base, lining under the back padding. A narrow-beam torch and an illuminated magnifier make inspection genuinely practical: to the naked eye, a 1 mm pearly-white egg is invisible.
• After an outdoor education trip, everything goes in the tumble dryer for 30 minutes at 60 °C before entering the bedroom. Dry heat is lethal at every stage, eggs included; washing alone, below 60 °C, is not.
• For a delicate comfort blanket that can't go in the washing machine or tumble dryer: 72 hours in the freezer at −18 °C in an airtight bag.
• If doubt persists, barrier-type detection traps for bed legs, placed under the frame posts, make it possible to establish their presence within a few nights without dismantling the bedroom.

Telling the school: the real collective lever

If you find bed bugs at home and your children are at school, inform the head teacher. Not so that the school can treat anything — it generally has nothing to treat — but so that it can space out coat hooks, replace communal coat racks with individual lockers, and inform other families.

France's inter-ministerial bed bug action plan has made this transparency without stigma a central pillar. The opposite reflex — hiding an infestation for fear of what others will think — is precisely what allows outbreaks to multiply across a neighbourhood. The French housing ministry and the national health safety agency (ANSES) regularly point out that a bed bug infestation has no link with how clean a home is.

Home treatment: what to avoid at all costs

Every new school year brings back the same procession of bad ideas, some of them dangerous.

"Home-made" insecticides and unauthorised products. State services have had to point out repeatedly that some products still sold online have been banned in France for more than a decade. Using an agricultural product, a repurposed veterinary product or an insecticide bought on a foreign marketplace in a child's bedroom amounts to domestic poisoning, not treatment.

Foggers and "total release" bombs. They do not penetrate deep harbourages and above all cause bed bugs to scatter towards neighbouring flats. An outbreak confined to one bedroom becomes a whole-building problem.

Misusing a steam cleaner. The tool is excellent — steam at over 110 °C at the nozzle kills eggs and adults on contact — but you must move very slowly, with a concentrated nozzle, taking care not to blow the insects further away. A high-temperature steam cleaner is a worthwhile investment for a household with children; a household steam mop is not.

Throwing out the mattress straight away. An understandable reflex, but often counterproductive: a new mattress in an untreated room is colonised within days. A full bed bug-proof encasement, with a lockable zip, traps the insects already present and prevents any new arrivals from settling in. Keep it on for at least a year.

For confirmed infestations, the only reliable route remains professional treatment combining heat, steam and authorised biocides, with at least two visits 15 days apart. Our price benchmarks are detailed in our article on the cost of pest control interventions, and you can have your situation assessed via our services.

The special case of resistant lice

For a few seasons now, families have been reporting repeated failures with conventional products. Two possible explanations:

1. Poor application — under-dosing, shortened contact time, no second application, siblings left untreated. By far the majority cause.
2. Genuine pyrethroid resistance, documented in several countries and probably present in France. It does not affect products with a physical mode of action (dimeticone), which work mechanically.

If two properly conducted cycles fail, a visit to your GP or pharmacist is called for: an oral prescription treatment exists in certain situations. Conversely, be wary of "natural" solutions based on pure essential oils applied to a young child's scalp — ANSES has issued repeated warnings about the neurological and allergic risks of certain essential oils in children under three and in pregnant women. Prevention with a hair repellent spray formulated for children, applied to the lengths before school, is a reasonable option; pure essential oil is not.

The September calendar, week by week

Key takeaways

• Lice don't jump, don't fly, and have nothing to do with hygiene: infestation happens head to head.
• A successful lice treatment always involves two applications 7 to 9 days apart, plus regular combing.
• No exclusion from school is justified for pediculosis; informing the school, however, is.
• Bed bugs almost never colonise a classroom, but they travel through cloakrooms and school bags.
• The single most effective prevention measure of the whole school year fits in six words: the school bag doesn't go on the bed.
• Never use an unauthorised product or a fogger in a child's bedroom: the health risk is real and the effectiveness nil.

To go further on detection and lasting eradication, see our complete bed bug guide, and our selection of detection and protection equipment in the shop.