Q: I am investigating worm farming to start a business and found that small-scale farming is done by feeding the worms waste food (like kitchen leftovers), and the worms will eat it and then excrete it, eventually making a rich compost for growing plants/crops etc. My first question is if this is something permissible to deal with on the small scale (where the food given to the worms is clean, but the resulting compost is actually worm excrement). When worm farming is done on a large scale as a business, the farmers feed horse manure to the worms because it’s a free or low-cost food for them, and available in large quantities. This is eaten by the worms, and again there is a rich compost that they excrete. My question is whether it’s permissible to deal with this, and also profit from a business in this manner. If it is, I would ask Mufti for some advice on what precautions to take to make sure that no Salaah or Ibaadat (act of worship) is put at risk due to making contact with any unclean material.
A: The rule is that the excrement of insects is pure. So this farming will be permissible and the excrement will not render you impure, irrespective of what the worms eat.
Moulana Yusuf Laher