Sounds like Fungus Gnat larvae, or springtails.
For Fungus Gnats, water in some Gnatrol Powder, or crushed up mosquito dunks on the soil and in the reservoir. Also, you can put some slices of potato on the soil and the larvae will crawl into them. Then remove the potato.
There are some good resources on fungus gnat control on forums around here. If they are jumpy, they are springtails and harmless to plants. Just try to keep the soil dry and avoid standing water under the plants.:jointsmile: