Over the last few weeks/months, we have noticed what I can only call pimples on a 2nd floor bedroom ceiling. The pimples are in a very small area (about 1 sq foot) in clusters of 10 or so. The pimples are hard, and the drywall seems intact around them. There are no signs of water damage. Can anyone tell me what these are? Are they condensation?

Thanks

Do You Have A Sink Or Toilet Above This Area? It Could Be A Wax Ring Leaking

Unfortunately, no. Above this room is empty attic space. The attic opening is very small, and the roof line is very low so its no practical to look at the ceiling from the attic. Thanks anyway for the response