Records from familysearch.org:

William Ayers in household of George W. Ayers, "United States Census, 1900"
Name: William Ayers
Titles and Terms:
Event Type: Census
Event Date: 1900
Event Place: ED 668 Philadelphia city Ward 27, Philadelphia, Pennsylvania, United States
Birth Date: Jun 1898
Birthplace: Pennsylvania
Relationship to Head of Household: Son
Father's Birthplace: Pennsylvania
Mother's Birthplace: England
Race: White
Gender: Male
Marital Status: Single
Years Married:
Marriage Year (Estimated):
Mother of how many children:
Number of Living Children:
Immigration Year:
Household Gender Age Birthplace
Head George W. Ayers M 38 Pennsylvania
Wife Annie Ayers F 31 England
Son George Ayers M 11 Pennsylvania
Daughter Parthina Ayers F 13 Pennsylvania
Son Alfred Ayers M 8 Pennsylvania
Son Frank Ayers M 5 Pennsylvania
Son William Ayers M 2 Pennsylvania
Mother Emily Ayers F 64 Pennsylvania

William D Ayers in household of George W Ayers, "United States Census, 1910"
Name: William D Ayers
Titles and Terms:
Event Type: Census
Event Year: 1910
Event Place: Philadelphia Ward 46, Philadelphia, Pennsylvania, United States
District: 1163
Gender: Male
Age: 12
Marital Status: Single
Race: White
Race (Original): White
Relationship to Head of Household: Son
Relationship to Head of Household (Original): Son
Birth Year (Estimated): 1898
Birthplace: Pennsylvania
Immigration Year:
Father's Birthplace: Pennsylvania
Mother's Birthplace: Pennsylvania
Household Gender Age Birthplace
Head George W Ayers M 47 Pennsylvania
Wife Annie Ayers F 41 Pennsylvania
Daughter Parthenia Ayers F 22 Pennsylvania
Son George W Ayers Jr. M 20 Pennsylvania
Son Alfred H Ayers M 18 Pennsylvania
Son Frank Ayers M 15 Pennsylvania
Son William D Ayers M 12 Pennsylvania
Mother Emily Ayers F 78 Pennsylvania