• The purpose of this study was to examine the epidemiology of human bites to children In a day-care center over a one-year period. This was a cohort study based on the injury log maintained on a daily basis by staff of the day-care center, as required by state licensure law. A total of 224 children was enrolled in the center during the study period: 29 infants (ages 0 to 16 months), 62 toddlers (16.1 to 30 months), and 133 preschoolers (30.1 to 72 months). One hundred four children were bitten one or more times by other children in the center, with a total of 347 bites. The bite rates (defined as number of bites per 100 child days of enrollment in the center) varied significantly by age group but not by gender for initial or first-time bites, with toddlers having the highest rate and preschoolers the lowest (infants, 0.7129; toddlers, 1.3672; preschoolers, 0.4193). Total bite rates (which took into account multiple bites per child over the 12-month study period) varied significantly by age group, with toddlers having the highest rate per 100 days of enrollment and preschoolers the lowest (infants, 2.1931; toddlers, 3.1300; preschoolers, 0.5611). Males and females differed significantly in total bite rates per 100 enrollment days within the toddler age group (males, 3.6683; females, 2.3096) but not within the other two age groups. None of the demographic characteristics available in this study distinguished between children who were bitten compared with those who were not bitten with the exception of number of days of enrollment. The circumstances surrounding the biting events were examined with respect to the activity of the child when bitten, the victim's location when bitten, body part bitten, and treatment by staff. The results of this study raise policy questions about treatment protocols for human bites of children in group child-care settings, the routine recording of biting events, and the ethics and practice of reporting such events to parents.