Ball bearings on the slide rollers?

So today I was walking thru the fiver, and I stepped on a ball bearing rolling around on the floor? Can anyone tell me if the large slide rollers on the kitchen slides are ball bearing supported? I assumed the rollers were just supported by a large rod thru the roller only. I wasnt sure if they were, but I cant think of where else a loose bearing could come from otherwise.

How about out of the pantry or a drawer rail ??

We had a tower revolving floor fan. The ball bearings were coming out of the housing when we laid it on the couch during travel times.

Thanks JnbHobe...you were right. Looks like the bearings were from one of the drawer rails. I would not have ever thought to look there. Havent found which one is loosing bearings yet.