Whether they did it or not, God encouraged the OT populace to pray to Him:
Quote:
1Ki 8:37  If there be in the land famine, if there be pestilence, blasting, mildew, locust, or if there be caterpiller; if their enemy besiege them in the land of their cities; whatsoever plague, whatsoever sickness there be; 
1Ki 8:38  What prayer and supplication soever be made by any man, or by all thy people Israel, which shall know every man the plague of his own heart, and spread forth his hands toward this house: 
1Ki 8:39  Then hear thou in heaven thy dwelling place, and forgive, and do, and give to every man according to his ways, whose heart thou knowest; (for thou, even thou only, knowest the hearts of all the children of men;) 
1Ki 8:40  That they may fear thee all the days that they live in the land which thou gavest unto our fathers. 
Many of David's psalms speak of crying out to God daily. 
Quote:
Dan 6:10  Now when Daniel knew that the writing was signed, he went into his house; and his windows being open in his chamber toward Jerusalem, he kneeled upon his knees three times a day, and prayed, and gave thanks before his God, as he did aforetime. 
Israel's spiritual state fluctuated.  I think when things were going good, when they "had a heart to serve the Lord," people actually had a personal relationship with God.  It was when they started trusting in the Law, "drawing nigh with their lips," that the spiritual collapse prior to the Babylonian conquest occurred.