Question
I have two tropical plants (i think they are types of indoor palms) on the main
floor of my house. I water them once a week and the soil always seems to
stay damp. I was just away for 9 days, I watered and fed them with 20/20
plant foot before leaving and had someone water them 7 days after i left.
When I returned I noticed there are hundreds of tiny warms in the soil, the
soil is practically covered in warms. They are about 2 cm each very thin with
lots tiny tiny legs. It is moist on my main floor and I see they are starting to
crawl out of the pot. None of them have made it onto the floor, they are
staying on the clay pot. Have you heard or seen this before? I imagine it is
probably fine for the plants, I am just worried they might infest my house.
Can I get rid of them without damaging my plants? Do you know why I may
have gotten them in the first place?

Answer
Hi Pamela,
  There are many kinds of soil worms and caterpillars that can infest the soil of houseplants. There are also many ways for them to get inside your home. How long have you had the plants? There could have been eggs in the soil or on the roots when you got the plants or repotted them.
They have probably been there for a while but were small enough in size and population to go unnoticed. While you were gone, conditions somehow became ideal for them to reproduce and spread out.
They are probably not fine for your plants. All plant and soil insects that infest houseplants can harm the plants in some way. Even soil insects and worms that do not actually eat plant or root material will disturb the soil around the roots and potentially damage delicate feeder roots.
There are a couple of ways to deal with this problem. You can try to drench the soil with a diluted chemical insecticide such as Malathion. This treatment will have to be repeated often since the eggs will not be affected by the insecticide. Before drenching the soil, remove as many of the insects as you can. Replacing the top half of the soil with fresh soil before each treatment would be best.

Since the infestation is so bad, the absolute best way to deal with it is to completely repot the plants into fresh soil. Once you have removed the plants from the pot be sure to remove as much of the old soil as possible. You can even rinse the roots with tepid water to remove all traces of the old soil and any eggs that might be clinging to the roots. If you are going to put the plants back into the same pots, wash the pots with hot soapy water. After washing, soak the pots in water with a little bit of bleach for about 20 minutes then rinse and dry.
To help prevent any kind of reinfestation, you can treat the plant with a systemic insecticide after repotting. A systemic insecticide that comes in a granular form and is mixed into the soil would be the best type to use. This will not only control any insects that feed on plant material but will make the soil inhospitable for soil insects, worms and caterpillars.

If you would like more information on insecticides and houseplant pests, here is a link to a guide I wrote on insect control on houseplants. It has a lot of information on the most common insects found on houseplants, the methods used to control them and the most common insecticides used.

http://reviews.ebay.com/Insect-Control-On-Houseplants_W0QQugidZ10000000004625662

** Always be careful when using chemical insecticides around children and pets. Keep in mind that they could possibly be harmed by plants that have been treated with toxic chemicals. For their safety it is always best to keep treated plants out of their reach.

I hope this helps. If you have any questions or need additional information please don't hesitate to ask.
          Thanks
              Tracy