Pest or Not?

I noticed, this evening, some very, very tiny insects crawling around near the soil surface of some of my bonsais. They are whitish or light gray in color. Are they anything I should be concerned about? I would prefer to just let them be if they are not harmful to my trees.

Larvae, beetles or flies??? A bit more info or a picture would help.

Probably psocids, which we have discussed before. Not usually harmful, but indicate too much dampness.
Iris

I would take a picture if I could but they are much too small. Smaller than a grain of sand. I don't think the pots are too damp though as the soil drys out within too days. I think they may have been stowaways in the root balls of the two ficus I got this summer because those seems to be the only two trees that have them. Could they become a problem or is treatment not necessary?

Actually, your soil should dry out overnight -- sometimes sooner.

Is the tree or trees indoors?

They are indoors for the winter now. I have never had my soil dry out that fast except on the very hottest of summer days. I use the same soil that Bill Valavanis uses...