Dear Evelyn, I’m hoping you can settle something that’s been keeping me up at night — and not because of the thing under the dock, which I’ve actually gotten used to. My family has owned a lake house in rural Tennessee for four generations, and for at least three of those generations, something has been living beneath the old boat dock. My grandfather called it a snallygaster, though I’ve looked that up and the descriptions don’t quite match — it’s never gone after livestock, it mostly just watches the water and makes a sound like a very large frog attempting to clear its throat. Every spring, without fail, it arranges whatever fish it hasn’t eaten into a perfect outward spiral on the dock planks. We always just swept them back into the lake. It became a thing we did. My grandmother used to say it meant the summer would be a good one, and honestly she wasn’t wrong very often. The problem is I’m selling the property. I’m relocating for work and I can’t keep up with the house from a distance. My realtor told me — very cheerfully — that I am under no legal obligation to disclose ‘non-human residents of unclear taxonomy’ in Tennessee, which, I have to say, is a sentence I was not prepared to hear from someone in a blazer. But legally permitted to omit is not the same as right to omit, is it? The new owners could be frightened. They could try to remove it. They could succeed, and then what? I feel responsible for everyone in this situation, including the creature, and I don’t know what the correct thing to do is. Sincerely, Marguerite

Your realtor is, to her credit, technically correct. She is also, I suspect, somewhat relieved to have found a legal framework to stand inside, because ‘non-human residents of unclear taxonomy’ is not a clause anyone drafts a form around on purpose — it gets discovered, usually after a difficult conversation in a parking lot.

But you are asking the right question, and asking it honestly, which already puts you ahead of a great many people who have written to me about very similar situations while pretending they were asking on behalf of a friend.

Here is my first piece of advice, and it is the practical one: disclose — not on the legal form, but in a separate letter, written plainly, attached to the listing packet or handed directly to serious buyers before they make an offer. You do not need to call it a snallygaster. You do not need to name it at all. You can say, truthfully, that a large semi-aquatic animal of unknown species has inhabited the dock area for at least three generations of your family’s ownership, that it has never caused property damage, never behaved aggressively toward people, and that each spring it arranges fish on the dock planks in a spiral configuration, which your family treated as a seasonal ritual and found, on the whole, agreeable. Buyers who find this disqualifying will remove themselves from consideration, which is useful. Buyers who do not find it disqualifying are buyers who will probably be fine. This protects everyone, including you from the particular guilt of knowing you handed something — someone — over to people who were not ready.

My second piece of advice is this: before you finalise the sale, go down to the dock once, alone, in the early evening, and tell it you are leaving. I know how that sounds. Do it anyway. In my experience, dock-dwelling creatures that have coexisted peacefully with four generations of a family understand transitions better than we give them credit for, but they do seem to receive the information better when it is delivered in person and with some sincerity. Leave something — a fish, if you can manage it, though I have heard that a generous handful of creek stones also works — somewhere near where it tends to watch from. This is not superstition. Or rather, it is superstition, but it is also courtesy, and the two overlap more often than people in blazers tend to acknowledge.

I should mention — and I will return to the point in a moment — that a reader wrote to me several years ago about selling a property in coastal Georgia with a similarly long-term resident beneath an old fishing pier. She followed much the same process I’ve described above, found a buyer who was, in her words, ‘an unusual man who asked very few questions and seemed pleased about the whole thing,’ and has since received a card from him every December. Last year’s card said the spiral was bigger. She considers this a good sign. I think she is probably right.

The creature under your dock is not a problem to be solved, Marguerite. It is a relationship to be handed on carefully. Find it the right next family, and tell it what’s happening. That is, I think, all any of us can do.