Nits and lice don’t just infest children and getting rid of them can be hard work – especially with their growing resistance to pesticides. Now a whole new industry is growing up to offer hi-tech solutions to this itchy problem.

This article will make you itch. I’m sorry. There’s no way round it. I’m pretty itchy myself, but that’s head lice for you. They warm themselves on Planet Scalp, sifting wisps with their antennae and, as the experts creepily put it, “taking a blood meal”. I have learned to recognize many types of itch since discovering two of the beasts in my hair. Some are a slow, creeping thaw on the head. Others, a fleeting tweak.

Between 8 and 10% of children in the UK are thought to have head lice at any one time and there are an estimated 6-12m cases a year in the US. But lice can also move from adult to adult. You might have hugged a colleague who has caught them from her children. They can ping from the static of a comb. Or maybe you tried on a hat in your lunch break, and a louse moved into its new home. Contrary to popular belief, there is no data to prove that men are less attractive to lice than women. Can you feel that tickle behind your ear yet?

Head lice have been around as long as humans. They have been picked, preserved, from Peruvian mummies, and pried from the teeth of a Roman soldier’s comb. Yet, despite our long acquaintance, humans know little about lice and what makes them tick. (On the bright side, they do know some lousy puns.) “I’ve combed my head obsessively, I’ve applied treatments, and still found only two lice and some unhatched eggs. How am I meant to know if I have caught them all?” As I speak, the colleagues either side of me stop typing. A few minutes later, they start scratching their heads.

If you don’t have lice, you can still catch delusional parasitosis – the mistaken belief that you are infested. One nit-removal professional told me that for weeks after she started her job she dreamed she was being chased by giant lice. They even infest your telecommunications: every time I text the word “love”, my phone autocorrects it to “lice”. Why, after centuries of medical advancement, have humans not found a way to eradicate them? Why are they so good at evading treatment? And is the anti-lice industry really doing all it could to help those of us at the ticklish end of the problem?