Due to their epithet ‘born’ and their beginningless actions the remain separated from Siva and are regulated by the happiness of their virtues and pains of their sins. In accordance with their deeds obtaining bodily forms, age and destinies of respective species, these ignorant species go on passing from birth to birth
Four kinds of Creatures:
Various kinds of Jivas are born on the earth a thousand times respectively in various gradiations of live, e.g. Udbhij or immobiles born out of the ground; Svedajaor mobile born out of sweat such as insects etc.; Andaja or those born out of eggs, such as, birds, etc.; and Farayaj or born out of womb, such as animals, men in different stages of development, Gods, and the Liberated Beings.
Superiority of human body :
Of the 84,00,00 bodily forms, human body is the most important, for it is this form in which one gets knowledge to the Essence. This knowledge of the Essence can not be attained in any other form than human. Even in hundreds of thousands of births, O Parvati ! when due to the accumulation of virtuous deeds, a human being with efforts obtains the knowledge of Essence he becomes Liberated.
Endowed with human form as a ladder for Emancipation if one does not liberate his Atman, then who can be a greater sinner than him.