jantur vai bhava etasmin

 yam yam yonim anuvrajet

tasyam tasyam sa labhate

 nirvrtim na virajyate

 

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 

 

The living entity, in whatever species of life he appears, finds a particular type of satisfaction in that species, and he is never averse to being situated in such a condition.

 

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 

 

The satisfaction of the living entity in a particular type of body, even if it is most abominable, is called illusion. A man in a higher position may feel dissatisfaction with the standard of life of a lower-grade man, but the lower-grade man is satisfied in that position because of the spell of maya, the external energy. Maya has two phases of activities. One is called praksepatmika, and the other is called avaranatmika. Avaranatmika means “covering,” and praksepatmika means “pulling down.” In any condition of life, the materialistic person or animal will be satisfied because his knowledge is covered by the influence of maya. In the lower grade or lower species of life, the development of consciousness is so poor that one cannot understand whether he is happy or distressed. This is called avaranatmika. Even a hog, who lives by eating stool, finds himself happy, although a person in a higher mode of life sees that the hog is eating stool. How abominable that life is!