According to the narrative found in the Vana Parva (Ch.122-5) of the Mahabharata, Chyavana was so absorbed in practising austerities on the side of a lake that termites built up their mound all over his body and only his eyes were left.
ɐkˈoːɹdɪŋ tə ðə nˈæɹətˌɪv fˈaʊnd ɪnðə vˈɑːnə pˈɑːɹvə sˌiːˈeɪtʃ.wˈʌnhˈʌndɹɪd twˈɛnti tˈuː dˈæʃ fˈaɪv ʌvðə mˌæhɐbhɐɹˈɑːɾə, tʃˌaɪɐvˈɑːnə wʌz sˌoʊ ɐbsˈoːɹbd ɪn pɹˈæktɪsɪŋ ɔːstˈɛɹᵻɾiz ɔnðə sˈaɪd əvə lˈeɪk ðæt tˈɜːmaɪts bˈɪlt ˌʌp ðɛɹ mˈaʊnd ˈɔːl ˌoʊvɚ hɪz bˈɑːdi ænd ˈoʊnli hɪz ˈaɪz wɜː lˈɛft.