Is it permissible to earn money from selling fertilizers produced from worm waste, and is worm feces impure, nullifying prayer if found on one's hand or clothing?

Worms are of four types: 1. Those that originate from something pure (tahir). They are pure while alive and become impure upon death, and their excrement is excused (ma'fu 'anha). 2. Those that do not have flowing blood (la nafs lahu sa'ilah). They are pure whether alive or dead, and their excrement is pure. 3. Cockroaches (saraseer al-kunuf). They are impure whether alive or dead, and their excrement is impure. 4. All other types of worms. They are pure while alive, become impure upon death, and their excrement is impure.

Based on the ruling of purity or impurity of worm excrement, the ruling on selling them is determined. It is permissible to sell them if their excrement is pure, and it is forbidden to sell them if it is impure, according to the majority of scholars, in contrast to Abu Hanifa. As for benefiting from worm excrement for fertilizing land, it is permissible, even if it is impure, as long as it is not sold. This is because "it is not permissible to sell the fat of a dead animal," but it is permissible to benefit from it.