[chris (OP)]

Apparently there has been a big surge in cases of headlice among young people. Researchers are blaming smartphones - and the selfie culture as people crowd together to get "in shot":

This is a report on the story by that reputable science source, "The Sun"

According to insect consultant, Ian Burgess, whom we've had on the Naked Scientists Show in the past:

Over the past few years we have seen an increase in older children catching head lice. 10 years ago it would have been rare to find lice in secondary school children, but it is now much more common. While the prevalence of head lice has not diminished, from our research we are finding that lice are spread more widely through the different age ranges, with younger children passing them on to older children.

This may be due to a change in social behaviour, such as ‘selfies’ and teenage girls in particular spending more time in close contact with each other. Head lice are caught from head-to-head contact and can spread very quickly. Parents should check their child’s hair once a week, using clinically proven treatments if live lice are found.

Lice are a normal part of childhood and not something that parents should feel stressed or embarrassed about. The fact children are so tactile during play means that they’re much more likely than adults to catch lice as they spread via head-to-head contact. Head lice do not have to be a nightmare to deal with as long as you use a clinically proven product rather than relying on old wives tales.

So beware whom you rub heads with!

[RD]

I was going to suggest selfie-drone as a solution, but that could be worse than head-lice ...
 

https://youtu.be/yQSh1MWIdVU?t=4m

[Fluffinbet]

Alternatively, there's the "selfie stick" which can be argued to be just as bad as the drone.

[chris (OP)]

Agreed!

Alternatively, there's the "selfie stick" which can be argued to be just as bad as the drone.

Agreed!

[Bored chemist]

An increase in parasites?- I blame the Tory government.
Seriously,  increased poverty may well be a factor.

[alancalverd]

The speed with which head lice can colonise a classroom is out of proportion to the speed at which the individual lice move. Indeed if you were a happy louse feeding on A's head, why would you suddenly decide to move into the unknown of B's tresses? More research is necessary!

[chris (OP)]

@alancalverd I would speculate that the nit does not know whose head it's feeding on and just randomly moves about between hairs, perhaps influenced by local conditions a bit - the presence of anti-nit shampoo might be a deterrent, for example. Thus, the louse/nit does not realise when it's transferring from one person's head to another; if two heads get close, such as during a selfie, the lice can move between the two.

And, you know what they say... "two heads are better than one..."

[Bored chemist]

...Indeed if you were a happy louse feeding on A's head, why would you suddenly decide to move into the unknown of B's tresses? ...

Essentially for the same reason that people "discovered" America before Europe was full.
It makes sense to expand in case local conditions get bad.

[alancalverd]

Wikipedia has some interesting ideas

Lice differ from other hematophagic ectoparasites such as fleas in spending their entire lifecycle on a host. Head lice cannot fly, and their short, stumpy legs render them incapable of jumping, or even walking efficiently on flat surfaces.

which is why the speed of infection is remarkable.

Unlike body lice, head lice are not the vectors of any known diseases. Except for rare secondary infections that result from scratching at bites, head lice are harmless, and they have been regarded by some as essentially a cosmetic rather than a medical problem. Head lice infestations might be beneficial in helping to foster a natural immune response against lice which helps humans in defense against the far more dangerous body louse, which is capable of transmission of dangerous diseases.

which is pleasingly counterintuitive.