What is it? (And is it dangerous?)

Examining the soil around the base of one of my BRT’s, I saw several of these little guys. What are they and do I need to treat the soil to get rid of them?

I have no clue as to the type of this little worm. When considering if it is dangerous or not, I would ask “how is the health of the tree?” If the tree is healthy, it is probably not dangerous. I might also ask about how much organic matter you have in the soil? If you have a significant organic component, it may just be breaking that down.

Hey Marty, thanks for responding. The tree was purchased from Wigerts about three years ago. Kept it in the nursery pot for a year, moved it to a rectangular bonsai container and then moved it to an Anderson flat to give the roots a boost. The soil is a 1:1:1 mix with about 5% of its original soil remaining near the base. There is some trunk rot at the base that I am going to have to repaair, probably next spring. But apart from these issues at the base and in the soil, the foliage and crown of the tree is very vigorous and healthy. I have a number of BRT’s from different stock that are also very healthy, so you are probably right. Nothing to worry about.