DUSTY, she thinks our house was dusty? This thought rolls in my head for a while, so I find a duster. I do know where those things are kept, you see.

I begin in the shower room downstairs, then start on the stairs, moving jugs and ornaments, and then running the cloth over picture frames, before dusting the top of the old clock that no longer ticks. Or tocks.

Then I go into the guestroom and dust the picture rail and other places she almost certainly didn’t see. She was quite short and could only have seen the picture rail by standing on a chair. And if she’d done that, she could have peered on top of the wardrobe, and – hands up – that is dusty. The dust up there has friends. Come friendly dust. It’s a dust party up there.

Dust has never been mentioned before. This explains why I feel cross. Mostly people remark on the house being clean.

After perhaps half-an-hour, I shake the cloth outside, then pop it in the washing basket in the for now less dusty shower room.

We always clean before guests arrive. We cleaned before the last one was due. That’s why the comment about dust stung, and then made me feel guilty.

I was meant to be preparing a lecture for next week, and doing some writing. Or looking for freelance ideas. But instead I was worrying about dust.

One of the strange aspects of Airbnb is that you rate your guests and they rate you. Most of our ratings are positive, and I’ve rarely had cause to give guests anything other than a ‘good’ score.

Sometimes you rate them before they rate you. That’s what happened here. I said something bland but pleasant about the young woman from India. In return, she mentioned dust. This isn’t entirely fair. She said something bland but pleasant about the house (one-all on that front) and mentioned that we are quite far from the centre of York (two miles from Micklegate Bar: it says that on the website), but that the buses were good. And that she enjoyed her stay. And we enjoyed her stay, too. She was a very pleasant young woman.

The passing comment about dust came in a section that could not be seen by anyone else. It was private – until I started going on about it just now.

There are people who give up with dust, admit defeat and let the dust to its own thing. We’ve never done that, but dust does always finds a way. Our attic bedroom is the worst. The hard floor is perfect for furry friends. Not long after you have vacuumed, dust gathers again, seeking out the corner by the radio. David Attenborough should come and film those fuzzy grey curls. I am sure their mating rites would be of general interest.

Here are two passing thoughts on dust. First up in my mind was the bit about ashes. When did ashes and dust first get it together? I wondered if it was from the Bible, but it’s not, or so a Google search suggests. “Ashes to ashes, dust to dust” is from the funeral service in the Common Book of Prayer.

That’s all we are, ashes and dust. What a cheery thought for a morning in January. I am not a religious person, but wonder for a moment if whoever is in charge keeps a final tally. If so it’s probably done online nowadays, and perhaps there is a section about dust. And ashes.

My other thought was simple enough: what is dust? Little bits of anything and everything, or so it seems, and containing various microorganisms. Dust looks dull but harbours all sorts of microbial life, apparently.

Online again, I find an American study with the title, “The ecology of microscopic life in household dirt.” The findings are too complicated for me to absorb or repeat here. But indoor dust is different to outdoor dust – and my dust is different to your dust.

The report said by way of introduction: “In particular, the female: male ratio and whether a house had pets had a significant influence on the types of bacteria found inside our homes highlighting that who you live with determines what bacteria are found inside your home.”

Personally, I blame the cat for the dust, but then I blame the cat for many things. In evidence I will ask you this: when does that cat ever have a duster in her paws?