The suspect agreed to let police send down coloring books, crayons and prescription medication that the boy needs for treatment for Asperger's syndrome and attention deficit disorder, State Rep. Steve Clouse told CNN.
Neighbors have said the bunker has electricity, and Dykes has been known to stay in it for up to eight days, said James Arrington, the police chief in nearby Pinckard.
Dykes has been described as a self-styled survivalist with "anti-government" views, according to the Southern Poverty Law Center's Hatewatch.
The incident called to mind another bus hijacking. In 1976, three masked men boarded a school bus in Chowchilla, California, taking 26 children and their driver hostage. They were forced into a buried vehicle, where they spent 16 terrifying hours before they were able to escape.
Jennifer Hyde was on that bus. She was 9 years old, and described what happened as the end of her childhood.
"You couldn't just go on and have a normal childhood when you faced a life threatening situation like that. You just can't go on and be carefree," she told CNN's Don Lemon.
She said her heart goes out to Ethan: "I can't imagine him being alone in the situation that he's in. At least I was able to have other children with me and one adult that I knew and could trust."
As negotiations in Alabama continue, preparations were under way for Poland's funeral.
Services for the late school bus driver will be held Sunday at the Ozark Civic Center.
Alabama Gov. Robert Bentley praised Poland for protecting the children on his bus.
"He stood in that place, and when that man came to take two children, he said no. And he lost his life because of that ... he did his job, and I'm proud of him as the governor but I'm just proud of him as a human being," he said.