The two killers carried out two years of sustained attacks on the toddler and two other boys as social services repeatedly failed to act.
The pair’s depraved abuse included imprisoning one boy in a cage made from a fire guard, using cable ties to bind his hands behind his back.
They also tied another boy naked to a chair in a dark room with nine snakes and several rats, forcing him to eat his own vomit and telling him a boa constrictor ‘ate naughty little boys’. They also forced the youngsters to take cold showers when they wet the bed
The two women arrived at the Stirlingshire prison on May 20 after incriminating themselves when they admitted failing to get Liam help for his broken leg.