In the Overhead Bin
A lesser known task of a flight attendant is to ensure that all infants are accounted for. This flight I was on had three, but I only saw two. I looked up and down the entire plane but could not find the third child. So I went to the guardians and asked them where their child was.
Apparently, they had never been on a plane before and put their baby in the overhead bin. Absolutely horrified, I took the baby down and reiterated that the child needed to be placed in one of their laps.