Sleep Problems: 24 Hour

Feedings in a 24 Hour Period

My son is almost 5 months old. He usually eat every 3 hours a 7 ounce bottle and an 8 ounce bottle before he goes to bed. Lately he is going 4 or even 5 hours without being hungry. When I try to feed him after 3 or 4 hours he just plays with the bottle alot and sometimes wont finish the whole thing. I have not increased the amount he gets and he is not getting solids at the moment so is this normal??