Neuter plural in Kannada:
In Kannada, the neutral gender singluar is adu. The plural form is avu. However, people have generally felt comfortable using avugaLu as the plural form. -kaLu generally form plural of a word in Kannada. Even in places where people use 'avu' for plural, they prefer to add -kaLu in various cases (eg. avugaLige, avugaLannu etc..).
I think the problem arises because both adu and avu were initially neuter singulars. As declensions appeared in languages these took various forms. In many Dravidian languages, male and female third peson pronouns were built upon neuter avu. For example, in Kannada, avanu -> he, avaLu -> she. In some languages 'adu' is the base word. For example, in Pengo, adel -> she. Interestingly, Kannada also has masculine form of 'ad'. The word Ata or Atanu could be found in literature though I haven't come across its spoken usage. Its feminine form Ake's origin is mystery to me.
In Kannada, avu became plural for adu. However, this appears to be largely a semi-optimization and never really taken by native speakers. Kannada speakers still by and large use 'avu' in singular sense though never as a singular term.