Sixteen children from the same family were rescued Tuesday from a dilapidated home in rural Ohio, where they had been living in squalid conditions, authorities said Wednesday. Human waste was found throughout the residence, and the children had reportedly been confined to a single room for much of the past four years.

Some of the rescued children were unable to speak, and an 18-year-old with developmental disabilities could not write her name, according to investigators. Vinton County Sheriff Ryan Cain described the scene as a "disgusting" one, stating that "most of our livestock was kept in better conditions than the children."

The children, ranging in age from 1 1/2 to 18 years old, were discovered by authorities while executing a search warrant related to an unrelated investigation. Ohio Attorney General Andy Wilson characterized the children's condition as "almost feral animals."

Officials indicated that it appeared no one outside the immediate family was aware of the children's existence, as they were not enrolled in school. "We didn’t know there were going to be 16 kids there," Wilson said, struggling to describe the conditions found in the small village of Hamden.

The sheriff reported that the children appeared to have spent most of their time in a room approximately 12 feet by 12 feet. While authorities did not find any cages, the exact method of confinement was not disclosed.

Seven of the children were transported to hospitals in Columbus, with two flown by helicopter. One child was in critical condition on Tuesday, while others were admitted for care. The children are currently in the temporary custody of the Ohio Department of Jobs and Family Services.

The children's parents and two grandparents have been charged with felony child endangerment, specifically second-degree, due to the "serious physical harm" involved, according to Vinton County prosecuting attorney William Archer. Gary Siders Jr., Gary Siders Sr., Christina Siders, and Elizabeth Siders appeared in court Wednesday, where a judge entered not guilty pleas on their behalf. Bond was set at $300,000 for each of the four adults, who have not yet been assigned legal counsel.

A spokesperson for the attorney general's office declined to confirm if all the children were siblings or specify their exact relationship to each other.

The family had reportedly moved around southern Ohio for the past two decades, and investigators believe they took measures to avoid establishing medical and government records. "These folks were pretty good at hiding these kids," Wilson said.

Investigators are examining whether the family had prior contact with any children's services agencies. A neighbor, Joseph Stewart, who has lived on the street for six years, stated he had not seen any children since the family moved into the house down the road and described the area as a "quiet neighborhood."

Hamden, located about 60 miles southeast of Columbus, has a population of less than 1,000. The discovery has drawn comparisons to past cases of severe child abuse, such as the Turpin family case in California, where 13 children were found to have been subjected to years of torture and abuse by their parents.