Incessant Beeping driving me nuts

[NameChangeABC2020]

Confession - bit of a hoarder, I meant to declutter a bit over the break but didn't.

Something electronic started beeping every 30 seconds as if its batteries/charge is about to die,
Spent a couple of hours going through stuff yesterday evening, still not found it - it's a high pitched bleep that's hard to locate the direction of - I felt as if it was moving about yesterday.
I did come across lots of useful things I'd lost.

Any suggestions what it might be, or how long it will go on for?

Wired in smoke alarms start beeping at 10 years old to ensure you replace them. When I bought my house the previous owners had flicked the switch in the fuse box to stop the noise rather than replace them. With that in mind could it be the flat below if you can’t find it, if there is one below that is.

Our DS's DGM bought cheap toys from the pound shop for all the DGC - primarily based on the youngest wanting one, but she wanted to treat them all fairly.

They look bit like a tiny computer games console and beep randomly and incessantly, regardless of which buttons you press. They sound like one of those old-fashioned unkillable musical birthday cards that you could stamp on, beat with a rock or pour boiling water over and nothing would stop the horrid tinny noise.

After getting boring very quickly, that somehow made its way down behind the sofa and did its nasty worst - took us ages to track it down.

Fit bit.
CO alarm.
Our fridge alarms if it has a problem and flashes an error code.

Oh my god I literally woke up with this same problem today!!

I've worked out what mine is though
Mine is DVR that I've got for my cameras. Mind I've no idea why it's doing it or how to fix it!!

thanks again everyone
No more displacement and delaying tactics - back to the boxes in the corner where I think the noise is.

.@DalzielOrNoDalzielAndDontPascoe - I bet you hated them for that

I had the flat gutted and refurbished when I bought it, so no lurking things in cupboards - and no flats below me.
Will post when I track down what it is.

Smoke alarm

Had this problem once. It drove me mad trying to find the source. Eventually I tracked it down - it was a meat thermometer.