2,289. Spontaneous Generation

Maachalos Assuros 2:13

Species that come into existence through trash heaps and animal carcasses, including maggots, worms and other things that are not brought into existence through a male and a female but from decaying filth and similar things (i.e., through spontaneous generation, as was believed for most of human history) are considered things that crawl upon the earth. One who eats an olive-sized portion of them is liable for lashes as per Leviticus 11:44, “Do not contaminate your souls with any swarming thing that crawls on the earth” – even those that don’t reproduce. Swarming things that swarm on the earth, however, refers to those that reproduce from a male and a female.

Maachalos Assuros 2:14

As far as species that come into existence from fruit and other foods, if they leave that food and go to the ground, then one who eats an olive-sized portion of them is liable for lashes as per Leviticus 11:42: “Any swarming thing that crawls on the ground.” This prohibits those that left their point of origin for the ground, even if they later returned to the food. However, if they never left the fruit, it is permitted to eat it with the worm in it.