Mahabharata 13.112.56

वानरो दश वर्षाणि त्रीणि वर्षाणि मूषकःश्वा भूत्वा चाथ षण्मासांस्ततो जायति मानुषः

vānaro daśa varṣāṇi trīṇi varṣāṇi mūṣakaḥśvā bhūtvā cātha ṣaṇmāsāṃstato jāyati mānuṣaḥ

Our plain-language meaning of this verse is waiting for scholar review.