Capo, they probably are centipedes/milipedes..I get the two mixed up, but those w/smaller legs.
I know they sell a poison that kills them, but if it were my tree, I'd take it outside, remove all soil, then repot in fresh. I'd also clean the pot. And toss old soil.
Some soils contain these bugs, and it's supposed to be sterile which is puzzling.
How you end up ridding these bugs is up to you, but if you plan on eating fruit I wouldn't want to put harsh chemicals in the soil..Toni

Capo, I use all purpose, peat and sand/perlite. About 1/3 of the first three mediums and a couple handfuls of perlite. Toni

I have adopted a mini orange tree. About 3 weeks ago I re- potted it and put it in Miracle grow Self release soil. Since that time the bottom leaves have turned yellow and some have fallen off. Does anyone have any suggestions of what to do or what not to do or even where I can go to get information on how to properly care for it?

Dev, it's normal for some leaves to yellow and drop after repotting, unless it happens daily and doesn't stop.
What is Miracle Gro Self release soil? Do you mean, slow-release soil? Does it contain fertilizer?

Perhaps this soil alone is too heavy..How long does it take to dry? How often do you water? Do you wait for soil to dry out before watering? Does your pot have drainage?
It's important citrus get as much light as possible, and water only when soil drys out. Toni

Hopeful,

It is self release. The tree is only about 3 feet tall, if that. The whole bottom of the tree leaves fell off. I water about once a week and do not wait for the soil to dry out. Do you recommed a different soil or water pattern? Thanks!

Dev, it's important the soil drys between waterings..if you keep it constantly wet, you'll have nothing but problems. For one thing your tree can get mold, but worse, root rot.
I don't believe in watering schedules..water only when a plant is dry..this applies to most plants, not only citrus.
There are different ways to determine if the soil is dry..one is by using a water guage; they go from 15.00 and up. The second is stick finger deep in soil..if your finger comes out wet, wait a few days and recheck..if it comes out dry then water..the third way is by lifting the plant..if it's heavy then soil is still wet..If light then it's time to give a drink..When you do water, do so thoroughly. Do so until water seeps out of drainage holes. Water in circular motions so all parts of roots get a drink.
Is your soil well-draining? Toni