The Snake replied O king, on account of their own (meritorious or evil) acts men are seen to attain one of the three conditions of rebirth as men, heavenly existence or birth among the lower animals.
सर्प उवाच तिगे वै गतयो राजन् परिदृष्टाः स्वकर्मभिः। मानुषं स्वर्गवासश्च तिर्यग्योनिश्च तत् त्रिधा॥