BROODED

To keep an egg warm to make it hatch.

"In some species of birds, both the mother and father brood the eggs."

To protect (something that is gradually maturing); to foster.

"Under the rock was a midshipman fish, brooding a mass of eggs."

(typically with about or over) To dwell upon moodily and at length, mainly alone.

"He sat brooding about the upcoming battle, fearing the outcome."