arvak-srotas tu navamah
ksattar eka-vidho nrnam
rajo ’dhikah karma-para
duhkhe ca sukha-maninah
arvak—downwards; srotah—passage of food; tu—but; navamah—the ninth; ksattah—O Vidura; eka-vidhah—one species; nrnam—of human beings; rajah—the mode of passion; adhikah—very prominent; karma-parah—interested in working; duhkhe—in misery; ca—but; sukha—happiness; maninah—thinking.
The creation of the human beings, who are of one species only and who stock their eatables in the belly, is the ninth in the rotation. In the human race, the mode of passion is very prominent. Humans are always busy in the midst of miserable life, but they think themselves happy in all respects.
The human being is more passionate than the animals, and thus the sex life of the human being is more irregular. The animals have their due time for sexual intercourse, but the human being has no regular time for such activities. The human being is endowed with a higher, advanced stage of consciousness for getting relief from the existence of material miseries, but due to his ignorance he thinks that his higher consciousness is meant for advancing in the material comforts of life. Thus his intelligence is misused in the animal propensities—eating, sleeping, defending and mating—instead of spiritual realization. By advancing in material comforts the human being puts himself into a more miserable condition, but, illusioned by the material energy, he always thinks himself happy, even while in the midst of misery. Such misery of human life is distinct from the natural comfortable life enjoyed even by the animals.
Link to this page: https://prabhupadabooks.com/sb/3/10/26