Averments in a pleading to which no responsive pleading is required or permitted shall be taken as denied or avoided. Averments in a pleading to which a responsive pleading is required are admitted when not denied in the responsive pleading, except that the following allegations must be proved:
Tenn. R. Civ. P. 8.04
Advisory Commission Comments [2009].
Even without denial of averments in an answer, allegations in a complaint must be proved in actions to terminate parental rights.