What is the custom for celebrating baby 4th month?

I didn't follow any custom when my baby turned 4 months old, but some Chinese like to follow this custom where they shave the baby's hair and let the baby taste different foods like drumsticks, a biscuit necklace and chives. Apparently it's to help minimise drooling. I personally do not believe in it. My baby doesn't drool much even though I didn't follow it. I suppose it's just for fun. http://www.missuschewy.com/2014/07/14/baby-chanelles-lunar-4th-month-traditional-celebration/ Like