How Do Harmful Bacteria and Carnivorous Beings Attain Human Rebirth?

How did bacteria come to be bacteria? If we trace back to the origin, there are no instances or evidence, nor can we find any basis in the Buddhist scriptures. Similarly, it is impossible to trace the origin of how harmful bacteria became harmful. However, harmful bacteria are only harmful to a portion of sentient beings and are not necessarily harmful to all beings in the Dharma realm, nor are they necessarily reborn as harmful bacteria forever. Life forms undergo transformations within the cycle of birth and death because, although microbial beings are extremely ignorant, they still possess extremely subtle mental activities and very faint karmic actions. As long as there are karmic actions, there will be karmic retribution, and life will undergo changes. As for large animals, when their karmic retribution ends, they will gradually be reborn as humans. For details, refer to the truth of the six realms of rebirth as explained by the Buddha in the Shurangama Sutra.

Large carnivorous animals were generally human in their previous lives. They committed evil deeds, which led to their rebirth as large animals. Once the evil karma is exhausted, they will naturally return to being human. The human body is a crucial turning point, where one can either ascend or descend. As for whether one can be reborn as the most ignorant bacteria, it remains unknown.