JBP small Bugs

[ml_work]

I re-potted my JBP the other day. Once out of the pot and removing the old soil I saw some (not too many) very small black bugs crawling around pretty fast. Far too small to even take a picture of. I have never seen them on the surface before and have watched this week, no sign of them anywhere on the tree. What could this be and how should I rid the tree of them?

Thanks,
Michael