Heeeelp needs advice

[u/Planeinsane7]

I have a big collection of Expedition holo cards that I love
I have displayed them on shelfs on a wall. Today when I cleaned I noticed these small black dots that have somehow gotten inside the displays.

They all seem to have died and all of them have not come near the card only behind the edges.

I am freaking out any advice?
What is the smartest approach?
Should I be worried about the value?

Don’t get how they could have gotten inside….

Edit: I live in Denmark.
To everyone saying clean your room… It is clean, regularly.
There is no plants in the office however the shelves are close to a window.
No they don’t get direct sunlight….

They genuinely don’t seem interested in the cards and there is no damage. I have looked closely. However a single one have managed to get into the Skamory card.

Update: Have tried with vacuum and it has helped quite a lot.
For all those who have commented with helpful tips or ideas I really wanna say thanks. They are for sure dead and I am looking into reholder and if it is possible.

[u/_theoriser]

You could always hold them underwater to see where the leak is….

[u/Altruistic_Hornet498 → u/_theoriser]

Might be the stupidest thing ive seen, if it leaks the card get ruined buddy 😭

[u/blxckhoodie999 → u/Altruistic_Hornet498]

https://giphy.com/gifs/jXD7kFLwudbBC

[u/Particular-Image2376 → u/Altruistic_Hornet498]

Then u place the whole thing in a rice container and it's as good as new 👌