The 1900 Census - Where Is Great Grandpa James Ed Womack?

My great-grandfather James Ed Womack was born in Wake County NC around the year of 1866. On the 1870 Census of Panther Branch, Wake County NC he was the youngest child of Handy and Prisseler Womack who were both thirty five (35) years of age, his name was James and he was four (4) years old. At that time he had one sister, Ines who was nine (9) years old and two brothers Thaddeus age seven (7) and Anderson age six (6). On the 1880 Census of Panther Branch Wake County NC the spelling of the family last name is now Wammach, his listed name was Edward and his age was given as twelve (12). His sister Ines is no longer listed in the home, his brother Thaddeus is now listed as Fabeus,age seventeen (17) and Anderson is age fifteen (15). In addition he now has two younger sisters Druscilla age ten (10), and Alma age two (2). His father Handy Wammach is now forty-three (43) and his mother Pricilla is now thirty-seven (37). Apparently Mama is not aging at the rate of everyone else! By 1900 the family has moved to Banner, Johnston County NC and Priscilla is now listed as Silla and is sixty (60) years old-->age has caught up with her now! Handy, Thaddeus (Fabeus), Anderson, Edward nor Druscilla are listed with the family. Alma is now twenty (20) years old. There are two additional children listed who are Thomas age 18 and Lula age 16. Two children listed as granddaughters to the head of the household are Estelle age six (6) and Hettie age(4. Since Alma nor Lula had any children I began searching for Ines and Druscilla. I found Ines, now Ida, still in Panther Branch Wake County NC. She was a servant in the Weathers household and is the divorced mother of two children. Hence I believe her to be Estelle and Hettie's mother. I have searched and searched the 1900 census for my great grandfather, James Ed Womack, and have come up with nothing. As I was discussing this with my sister she reveals she is having the same problem with my OTHER great-grandfather who also lives in NC. Ben McNeil and his first wife Lizzie Hall McNeil are missing from the 1900 Alfordsville, Robeson County NC Census. Is that a coincidence or is a part of the census missing? Was there a certain area that was skipped on the 1900 census? Why are other relative so easily found but not them? At the time of the 1900 census both James Ed Womack and Ben McNeil are married with at least one child (judging by the 1910 census) but still no record is found. Looks like I have another mystery on my hands!