Loads of tiny spiders on the ceiling!! Help me get rid of them..

[Mouldypineapple]

One night a few weeks ago, then again last night and tonight loads of tiny brown spiders (3mm big ish) have appeared in clusters on the ceiling in DD's bedroom. I have cleaned them off with disinfectant wipes but clearly more just come back! Help!!
Can't work out where they come in although possibly an air vent on the wall. Room is cooler than rest of house as 3 external walls, and does suffer slightly with damp esp. now weather changing. Any tips for that too??
Thanks..

Hoover.
Nozzle attachment.

Definitely Hoover. I had this problem as they were coming into the room from the loft hatch. I would put money on them coming from that air vent. can you unscrew it and look for the ball of spiders that have hatched? I kept hoovering and once I got the big ball of them, it was done. You can usually wash the inside of the vent and get rid of any creepy crawlies/eggs.

Hoover Hoover Hoover. That's all I do. Must be time of year as I found some the other day.