Cochlea & Eustachia

Cochlea and Eustachia appear to be twin human girls, but this has yet to be confirmed. Motivated by what appears to be purposeless destruction, they are out to cause mischief. Any objective they have remains to be determined, but they never stray apart from each other. Perhaps it is their resemblance to each other that keeps them close? They seem inherently suspicious of outsiders, and are accused of hypnotising cats to do their will. Just who are these meddlesome twins? And what do they want?