Tohoros 9:8-9

Tohoros 9:8

If a dead sheretz (vermin) was found in a mill’s stones, only the places that it touched are rendered unclean; if liquid was flowing, then everything is rendered unclean. If the sheretz was found on the olive leaves (a covering layer), they ask the olive pressers to confirm that they didn’t touch the sheretz. If the sheretz touched the heap of olives, even by as little as a hair, then the entire heap is rendered unclean.

Tohoros 9:9

If the sheretz was found on a small heap of olives that was on top of the large heap, and if it touched the volume of an egg, then everything is rendered unclean. If it was found on a small heap that was on top of another small heap, then even if it touched the volume of an egg, only the place it touches is rendered unclean. If the sheretz was found between the wall and the olives, they remain ritually clean. If the sheretz was found on the roof (after the olives were brought there), the vat remains ritually clean; if it was found in the vat, the olives on the roof are unclean. If the sheretz was found burned on the olives, they remain ritually clean; the same is true of a worn-out piece of cloth. This is because all cases of ritual impurity are judged as of the time they’re discovered.