We had a fairly unsatisfactory Skype session with Olive at the weekend: all false starts, frozen images and disjointed sound, but it was better, far better, than nothing. The gist of it is that she doesn’t much care for Thailand. This is partly because she lost a bit of her heart to Cambodia, to which Thailand is now unfavourably compared, and partly because both she and her travelling companion are covered in bites, which have become infected. She tried to hold her legs, ankles and arms up to the computer and we made sympathetic noises, although, in truth, we couldn’t see a thing. We suggested Savlon, but she’s run out.

She’s inherited my blood. I’m not keen on insects, but they’re very keen on me, as they are on Alfie, who was so severely midged on the west coast of Scotland last summer that, on the flight back, the American sitting next to us leant across and drawled: ‘I don’t mean to be rude, but does he have the pox?’

Whenever abroad, I lie under the sheets listening to the whine -or, worse, the silence-of the mosquito, but Zam is entirely unaffected and says I should take the sated mozzie as a compliment, a comment that’s not taken in the spirit in which it’s given. But this time last year, while staying with a friend in Dorset, it was Zam who was bitten as he walked through some long grass back to the car. The bite itself was painful and the resulting wound grew and grew until his ankle had tripled in size, was beetroot in colour and slightly blistered. He was sure he’d been bitten by a snake.

At various school events the following week, he rolled his trouser up to ask any passing parent to take a look. He considers mystery medical conditions an excellent conversational topic and he also hoped for helpful diagnosis. People visibly recoiled while covering their eyes until one, a GP, said Zam really ought to get some antibiotics. The source of the bite was never identified.

But now I’ve chanced upon what I believe may be the explanation and, really, it’s like a bad joke. I have, so far, managed to avoid large chunks of the world on account of their excessive bug life. I don’t mean to suggest that a long-haul flight to South America or Australia are daily hazards-I’m just saying they’re not on my list, their natural wonders including (and being overshadowed by) some scary-looking insects, principally spiders. We did once go as far as the Seychelles, but nobody had told me about the arachnids the size of dinner plates that hang from the telegraph poles on Mahé and I will not be returning.

Yet it transpires that we’re moving to an area that has its very own species of bloodsucking fly, whose female likes to feed on blood-preferably human-before mating: the Blandford fly. I’ve only just discovered its existence, which confirms a lesson I learnt from a painter friend of ours who-I don’t think he would mind my saying-takes his health pretty seriously.

While on a boat trip on the Nile, he was so worried about coming into contact with the river that he used bottled water for his paintbrushes. A fellow boat-dweller made her way to the loo in the middle of the night, but, owing to her severe short-sightedness, missed a step and fell into the famous river, creating a splash that flew up and then down, straight into the sleeping painter’s open mouth.

In other words, you can take all the precautions you like, but you will eventually be undone. I may have blacklisted large chunks of the atlas, to which Thailand is now being added, but then I get thrown a curve ball in the shape of our very own nasty little native-which is also known as Simulium posti-catum-whose bite has sent people to hospital. On reflection, I’ll probably never see one and perhaps it will be the only insect that prefers Zam. I can live with that.

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