In order to quantify age-dependent acquisition of a bloodmeal, we compared bloodfeedingpatterns of Aedes aegypti and Aedes albopictus starting from the time of first responsiveness to a bloodmeal upto 15 days postemergence. In separate experiments, cohorts of Ae. aegypti and Ae. albopictus of known agewere offered their first bloodmeal from a silicon-membrane system or a restrained chicken. For cohorts rangingfrom 3 to 15 days old, the proportions feeding were significantly affected by species, age, feeding protocol, andthe age X feeding protocol interaction. For both feeding protocols, a higher proportion of Ae. aegypti than Ae.albopictus, on average, consumed blood. Regressions of proportion feeding versus age indicated significantlypositive slopes for Ae. albopictus and Ae. aegypti on the membrane system, and no significant relationship wasobserved for either species on the restrained chicken. Additionally, slopes for Aedes, as a group, fed on themembrane system were significantly different from those fed on the living host. For both Aedes species fed onthe restrained chicken and for Ae. aegypti fed on the membrane system, the proportions feeding exhibited periodicpatterns, with peaks approximately 2 days apart, suggesting possible control by endogenous rhythms.