Ok, please do not try this without checking it out first. Here is my story. I had this problem more then once. The first time I got these crawly threadlike things in my soil (ie. Last summer), I ended up throwing out my Thanksgiving Cactus. So last November, I purchased a few more Thanksgiving Cactus from the supermarket. I noticed those pesky tiny fruit flies/knats flying around my plants. ( they usually lay their eggs in the soil ) Well that was it! I mixed a combo of rubbing alcohol and water and sprayed the surface of the dirt on my newly purchased plants really well. I have knat/fruit fly traps all over...ie.. Near each plant. For the first time since the Fall, I recently saw the first little bugger and put out my traps. I may do my alcohol/ water spray again. But this is risky. It did not kill my plants, but it can kill them if you overdo this. Proceed at your own risk. Best to try to control this problem. I do not think you can completely avoid it if you have live plants in the home. They LOVE organic soil and there may be unhatched eggs in the organic soil you buy at the garden center to transplant your thanksgiving cactus into a new pot in the Spring. So far I have NOT transplanted anything. Nor have I fertilized anything. These tiny fruit flies/knats come in through screens or with your groceries/fruit that you buy at your local supermarket. They can even come up out of the drain in your sink! I have added photos of these traps. They work well so far for me. You can purchase them at Home Depot or True Value Hardware.

Use some seaweed mix with fish emulsion and in a few weeks you will be fine best to stay away from Miracle Grow if you plan on actually eating from your plants, peppers do so much better on natural components rather than synthetic ferts... Here is a link that might be useful: Organzmo Peppers

I have caterpillar's that look similar, in that they have no obvious legs. But some are brown (slightly striped) and some bright green. They are eating leaves voraciously in my greenhouse and the basil in particular is struggling to grow faster than it is being eaten. I remove a kill as many as I can find but especially the green ones are hard to spot. It's now only August and some of the links above suggested that these larvae are only laid in late summer, and I've had the problem since July, and maybe earlier (but i first guessed slugs as i have lots of those too but pellets have more or less one that battle for the moment) HB

Thanks for the advice everyone! I decided to re-pot my tree (and take advantage of one of the first warm spring days). I ditched the self-watering pot and replaced it with a pot which will allow the tree to drain. I used a 5-1-1 mix and got some filtered water. It looks like the bugs were just chilling out in the soil. The roots actually looked very healthy- no sign of root rot. Some of the new growth had a little bit of a shock immediately post re-potting but has perked up considerably overnight. Next step: I'm going to wait a week or so until I fertilize. Any recommendations about fertilizer ratios?