viṣakṛmi nyāyaḥ (worms living in poison)
Some worms are born and live in high poisonous matter.
What one being's food is for another a poison. In Bhagavad-gītā living entities are described as sarva-gataḥ. That means they live everywhere. They live in water, on the bottom of the ocean, within the earth, wood, stool, fire, or in subtle elements like ether, mind, intelligence, and false ego. Therefore it is no wonder that they live also in poison. Actually, the poison is like nectar for them.
There is another important point connected to the previous one. Why do certain creatures live in obnoxious, and deadly stuff? This is all because of their sinful attitude. In other words, they more or less knowingly rebelled against God's laws governing spiritual existence, and specifically, those laws meant for human beings. Since they performed acts with the worm mentality in their human existence, prior to worm's existence, naturally they aim at such nasty goal of existence. One can just observe what are humans preoccupied with, which actually suits the animal state of consciousness. After sufficiently being frustrated with that low existence, gradually after a long period of time, the living entity again comes to the human form of existence to get another chance. This is the power of māyā, the illusory potency of the Supreme Personality of Godhead.
All this is visible to us, only to understand, and reform our independent rebellious mentality. Actually, from the higher point of view, our so-called advanced human civilization is deplorable, similar to that of the stool-worm. One need not to be proud of one's temporary superior human position. It is absolutely necessary to humble oneself before the unfathomable greatness, and power of God, and feel like a little worm. Then there will be no inferiority or superiority complex and suffering accompanying that.