

Oh, many years ago I had a baby monitor that included a pressure mat. If it detected no movement for a while (it was sensitive enough to detect breathing) it set off an alarm.
Although if such a thing exists today, it probably requires an app and a subscription. Enshitification.
I heard of it from this video
https://youtu.be/9Ch4a6ffPZY
It’s just one of several tells. Although you can’t really rely on anything. Just like “badly-drawn hands” is less likely to show up now.
Once I heard this, I had to learn how to type them, btw!