The PIT looks at the composition of the household on the last day in January.  If a child was admitted to the household after that PIT date and only adults were in the household on the date of the PIT, then the household would be counted as "adults only."  However, that same household would be counted on the APR as "Household with Children and Adults" on the PIT date - even if the child's household start date was after the PIT date - as long as the child joined sometime during that APR reporting period.  This is an intentional coding difference between the two reports, based on HUD specifications.