Carpentry and Woodworking - staircase screeching

The inner stairs has recently begun to make noise when climbing or descending.

i am kind of inclined to blame this on my kids who run up and down the steps

They are alll adults and would stop immediately

We had a similar problem on some carpeted stairs. My father pulled back the carpeting and found the stringers and "studs" beneath the stairs. He pulled up the treads of the bad steps and removed any nails. The nails are what made the noise. They squeak as they slide in and out of the old hole that they were driven into. My father replaced the nails with some deck screws that were considerably longer than the old nails. This allowed them to seat firmly into new wood and hold tight. I am also sure that he doubled the quantity to be sure that they wouldn't loosen up again. He then replaced the tread, the carpet pad and carpet and they are quiet as a mouse. The stairs used to lead to my room, which is now their room. They caught me nightly trying to sneak in and out of my room as a teen, now I can go up and down the stairs without notice. It's just not fair. :)