Teeny bugs, please help!

[Iusedtobecarmen]

Please help ASAP!
Have found these tiny black bugs on sons bedroom wall. Microscopic. On the one wall(outside). Can barely see them unless shine a torch. The wall seems damp. No mould. But last night, when I spotted them ,parts of the wall were wet.
I wiped the wall with white vinegar but it was late and dark.
Son slept downstairs(he is an adult).
I'm going to start marathon clean up today.
I'm thinking these are some kind of mould mites?? What can I do?
I open windows every day. Air the house.
Thinking need dehumidifier.??

Room was only redecorated in the spring.

Anyone?

Does your son have plants or food in his room? I've had some tiny flies round a Peace Lily I repotted. I think they might be fruit flies. I sprayed them with fly spray. They stick to the walls in the bathroom which get condensation on them. Maybe try a dehumidifier and removing any plants.

No plants no. He does sometimes eat upstairs but he doesn't leave food around as such. I'm ordering a humidifier!!