G.S.
How many ounces does he get during the day? If he's eating 32 oz. a day and is still hungry, then it's time to introduce solids. I wanted to wait until 6 months for my daughter, but we started at 5 1/2 months because she was so interested in what we ate. While her sleeping habits didn't change when we introduced solids, my nephew's did in a obvious way.