The Eisenia fetida, have two requirements regarding their habitat to be able to survive, namely moisture and food. Let’s look at a few aspects we will consider:

1. These worms require a humidity of 50-70% for survival. Any conditions dryer that this is not suitable, which will result in worms dying.  This is the main reason why we keep these worms in bins, and when farming with worms (on the scale we do) we keep them under irrigation.

2. Food – These worms mainly feed on soft, moisture rich food, such as veggies and fruits. Garden refuse should be treated or very “old” and have a fine texture, before it can be decomposed by these worms.

3. Soil composition – These worms were not created by God to burrow deep into soil. They prefer living in the very top layer of soil which should consist out of plant “debri”. If this “rotten” plant material is not present, they will have to survive in the top soil layer. In our climate conditions, the top soil gets the most sun exposure which causes the temperature to rise to high and that the moist is removed from it. This will cause the death of the worms.  

4. When using the worm-tea, worms cocoons are not placed back into the veggie patches.  You can place the compost back into the gardens, but then to prevent the worms from spreading into it, the worms and cocoons need to harvest before you use the compost.  A method which can be used is by diluting the vermi-compost in water, making sure your cocoons are removed.  This liquid can then be applied into the gardens. This is however not required, but should you prefer, we will include this process in the training of the workers.

5. As far as we know, there are different types of earthworms present in all compost piles, and they “appear” when conditions are favorable.  No study that I could find, indicated that these worms are any bad for the environment.  I did come across a study in the rainforests where the decomposition was so fast, that there was too much compost for the trees to use, and this caused rotting of trees, not by the Eisenia fetida, though.  I do not think this is a danger in our climate.

6. With all surety I can say, that there should be no “escapees” from the bins.

The harvesting should take care of the rest.  Should we get any other “AWAP’s” these will do no harm, rather be a plus to the current environment and soil composition.