We do it with wild animals and endangered species of migratory birds. Same diff, right? They're all unpredictable creatures who take off when you're not looking and get themselves into all kinds of trouble.

I'm still sort of surprised this hasn't become a thing yet, though I guess iPhone's 'Find Friends' is almost as good.

Of course, it's not just naughty kids that are prone to wandering. I was thinking about it this week after my little grey cat, Winter, didn't return for dinner on Saturday. Or breakfast on Sunday. By Monday, I'd (irrationally) checked the shed six times and we had exhausted all our ideas of where she could be, with no success.

It brought into view the shortcomings of the pet microchip technology, which is handy if anyone had found her but not much use if she'd been bitten by a snake and crawled off to die under a bush.

We'd never have known.

Of course, much as we love her, Winter is just a cat. But people go missing too.

In the world of psychology, grieving a missing loved one is called 'ambiguous loss', and it can be worse and more prolonged than 'ordinary' bereavement, due to the lack of closure.

Studies show that the unconfirmed loss of a family member produces more distress in loved ones, compared with enduring a confirmed loss. High levels of severe depression, including suicidal thinking, are not uncommon.

It's the stress of swinging between hope and despair, sometimes for years, that makes this a particularly dreadful predicament.

Meanwhile, Winter turned up meowing at the door on Tuesday morning (then she gulped down her body weight in Whiskers). We were delighted, but also - in the way that I used to be with my little bolters - a bit angry. How dare she scare us like that!

It might sound like something from a police state or a dystopian novel, but I would be secretly relieved if we all wore tracking devices, or at least used them on our pets.

(Quietly Googles "subcutaneous GPS tracker"...)