Investigators have said they suspect foul play in the 21-month-old child's disappearance.
State police spokesman Steve McCausland told WGME-TV in Portland, Maine, Tuesday night the search would center on the Waterville area but the exact locations wouldn't be announced until later.
Ayla has not been seen since her father, Justin DiPietro, put her to bed at his home in Waterville.
Her mother, Trista Reynolds, told WMTW-TV in Bangor she still isn't getting "the whole truth" about what happened the night Ayla disappeared.
On Tuesday Ayla's grandmother, Phoebe DiPietro, told CNN she had been at another location that she refused to disclose the night Ayla disappeared. In earlier public statements, she indicated she was among adults in the Waterville home where the baby had been.
She said police were aware of her whereabouts from the start of the investigation.
Ayla's parents are not married and don't live together.