cramped 12-by-12 room at their home in the small village of Hamden in a scene Ohio Attorney General Andy Wilson called  pure evil.  New York Post

The children, who were never enrolled in school, can barely communicate - and some cannot speak at all, authorities said.

The oldest child, 18, is developmentally disabled and unable to even write her name, according to investigators.

Grandparents Gary Siders Sr., 73, and Christina  Lynn  Siders, 67, were arrested alongside their son, Gary  Bub  Siders Jr., 36, and his wife, Elizabeth Siders, 33, and each slapped with 16 counts of felony child endangerment charges.

The younger couple is believed to be the biological parents of all 16 children, officials said.