CHICAGO (AFP) - A mentally disabled woman and her child were forced to live in an Ohio basement with snakes and pitbulls and were treated like slaves for more than two years, United States (US) prosecutors said on Tuesday.

The woman finally escaped by stealing a candy bar and telling police she'd rather go to jail than go home because her roommates "were mean to her". Three of her tormentors were arrested on human trafficking charges.

"We are yet again reminded that modern-day slavery exists all around us," said Steven Dettelbach, US Attorney for the northern district of Ohio.

"The victims in this case endured violence, threats, sub-human living conditions and other horrific acts."

The woman, who was not named, was tricked into moving into the crowded two-bedroom home in May 2011, prosecutors said. She was made to stay with repeated threats that her child would be harmed or taken away from her if she didn't do as she was told.

The woman and her child were initially forced to sleep on a cement floor in a locked room that also housed a roaming iguana.

They were repeatedly threatened with the pit bulls and snakes and watched with a baby monitor, prosecutors said.

On at least three occasions the woman was badly injured so that she could get prescription pain killers for her roommates: Jordie Callahan, 26 and Jessica Hunt, 31.

The woman's child was kept locked in a room while she was forced to do housework and to take care of a menagerie that included a poisonous coral snake, a ball python and a Burmese python that weighed 130 pounds (59 kg).

She was also forced to hand over her government benefit cards and was rarely given any of the money, prosecutors said.

The roommates withheld food from their captives as a means of intimidation, giving them only canned goods or what was left over after Callahan, Hunt and Hunt's four children finished eating.

The woman was given fruit and vegetables to feed the iguana but told her child couldn't eat any of the fresh food.

At one point when she complained that her child hadn't eaten all day Callahan got a plate of food and gave it to a dog out of spite, prosecutors said.

"The streets are a lot safer with these folks locked up," Ashland Police Chief David Marcelli said in a statement.

Also charged in the case was Daniel Brown, 33.