Late last year, the national animal advocacy organization PETA began to call out Festus-based Missouri Primate Foundation, alleging the non-profit was actually a "filthy" home where sixteen chimps "live amid trash and their own waste." PETA then threatened to sue the organization, saying the chimps' living conditions constitute an illegal "taking" under the Endangered Species Act.But now the Primate Foundation is going on the offensive — with a lawsuit seeking to bar PETA from filing any such suit.…