So this is something I've seen.
I noted it with a colleague and food.
Situation, Monday mornings we get free pastries to accompany our team meeting.
Sometimes there are left overs which we put in the kitchen.
Said colleague took a call whilst he was in the kitchen, got distracted and started fumbling one of the croissants.
Instead of taking it with him or throwing it away he left the partly destroyed croissant on the board.
Having seen this, I got a piece of tissue and picked it off the board and threw it in the bin.

Now whenever there's pastries I make sure I get mine before said colleague has been near them.

Could this be nervous energy? Could this be a power thing? Could this be some kind of absentminded behaviour? Could this person just not even be aware theyre doing it?
Honestly I don't know. But it's not great. It's unfortunately part of working with others .

You need a barbed wire electric fence to keep out the wildlife.

My late husband and I frequented a restaurant where we loved the food, but where an annoying manager would come and sit down with us for 15-20 minutes. I whined to my husband that he was so annoying. My husband went to his shop in the basement and made a lovely little easel stand of wrought iron with a fancy sign with the NO symbol and at the bottom, “No managers please. “ and the next time we went there, he pulled the sign out and set it on the table.

We were unbothered with managers after that.

We have had a clear/hot desk policy for years so there are rarely moveable objects on our desks to be interfered with.

I can remember in a previous job it was part of my morning routine to lay out five coloured pens in an order that was convenient for me to annotate a document. So of course people loved to mess that order up or put the pens on top of a cupboard where I could not reach them 😞

And managers wonder why people are reluctant to return to the office 🙄

Trying to show off their multitasking skills? But, yeah definitely odd behavior, though I personally think, I've never seen it myself.

Eh, Ive had this habit in the past. Not justifying it but it's almost an involuntary thing when you have uncontrolled and ADHD and you arent aware and working on controlling it.

It's a weird nerveous habit with adhd that we do until we are made aware of it and choose to worknon controlling it.

No.
If I do notice something interesting, I usually just compliment it or ask about it.
I don't mess with other people’s stuff.

Nope, that is not normal.
Hopefully you ate only dealing with 1 person who does this?

Some people are unaware of what they are doing; it's amazing really.

atleast they didnt put your stapler in a jelly (jello)

Once in a while. Maybe the movement of their hands helps them think.

No it's not.

Tell them to stop, hands off

I never worked ina office sounds crappy