You met Arnold on the “Aruba to Santa Marta” post. Arnold is the mouse – and he’s still here.

Obviously, I knew from the beginning that he couldn’t stay – a mouse on a boat is a recipe for disaster – what with their habit of chewing through electric cables and (heaven forbid) inlet hoses. It’s amazing to think that something so small could sink the boat – but he can – and unless I can find a way to get rid of him, he may well do just that.

My first thought was that I would get one of those humane mouse traps. I looked them up online: clear plastic, so he won’t feel claustrophobic while waiting for me to release him into the marina rubbish dump.

The dump is not such a good idea, since it is teaming with cats – but it is better than the skips in town which have been stripped of anything edible by the street people who live around them (sometimes, I believe, in them.)

It didn’t make any difference because the man in the hardware store had never heard of a “humane mouse trap” – even when Google Translate explained that it was a trap that did not kill the mouse.

What was the point, the man in the hardware store wanted to know, of a mousetrap that does not kill the mouse?

This gathered quite a crowd around my phone: A mousetrap that did not kill the mouse? Surely the microchips were mistaken…

It’s just as well that I learned early on to say “I’m English”. It explains a lot over here.

Since I could hardly wait for Amazon to deliver a humane mousetrap to Colombia, in the end, I bought the lethal version. Actually, it’s more of a rat trap – about twice the size of the ones we have at home and with a spring that really needs both hands. I baited it with a piece of mushroom (Arnold has demonstrated that he’s partial to mushrooms).

The next morning the mushroom was gone. The trap was still set and there was no sign of Arnold.

So, I looked up advice on YouTube and tried the next night with peanut butter – peanut butter cannot be removed delicately by tiny hands. It has to be licked off which is more likely to lead to a sticky end.

Arnold licked what he could safely remove and left the rest. It reminded me of leaving mince pies for the reindeer.

So, it was back to the hardware store, this time to buy rat poison. I really didn’t care for this at all – a quick end is one thing. Condemning Arnold to a lingering death – and then having him decompose in the farthest recesses of the bilges seemed most distasteful.

But needs must. I topped the peanut butter feast with a dessert of sodium monofluoroacetate, strychnine, zinc phosphide, aluminium phosphide, elemental phosphorus, arsenic, and barium carbonate. It came in the form of a sort of blue cake.

The next morning I got really quite excited on discovering that although, once again, the trap had not been sprung, almost all the peanut butter had gone and – best of all – the blue cake was missing from the top of little spike which is supposed to set the thing off at the slightest touch.

Or not. It turned out that the cake had been removed most carefully – and disposed of at a discrete distance from the feast.

I’m getting fed up with this. Tonight, I shall make a crumble out of the blue cake and mix it with the peanut butter. Surely, even a mouse as cunning as Arnold could not separate the two – which means he will probably leave the whole serving and help himself to some electric cable with a side order of plumbing.

Meanwhile, any advice would be gratefully received.