The purpose of the present study was to determine whether the susceptibility to seizures induced by inhalation of flurothyl ether (FE) varies with age. Adult rats and 16-day-old rat pups were tested in different sized chambers to also determine whether the size of the FE-test chamber influences seizure thresholds. Results indicate that pups developed age-specific seizure patterns; their seizure latency thresholds were shorter than those of adult animals. For both age-groups, seizure thresholds varied as a function of chamber size; the smaller the chamber the faster seizures occurred.