As part of an integrated series of experiments designed to provide a comprehensive picture of the behavior chicks exposed to 450-MHz fields that are modulated at EEG frequencies, a total of 24, 23-hour-water-deprived chicks, ∼ 12-day post-hatch at the beginning of the experiment, were exposed to 3- and 16-Hz amplitude-modulated fields at a power density of 1 or 5 mW cm−2 (n = 12) while performing on a fixed-time 30-second (FT-30) schedule of water reinforcement. Reinforcments were in no way dependent on the subject's behavior and were delivered every 30 s for a 2-s period. (Training on an FT schedule leads to an increase in the amount and temporal regularity of motor activity that occurs between successive reinforcements.) Sessions were divided into three 40-reinforcment epochs: the first and third epochs were used as control periods (the field was never presented), while the middle epoch was that during which sham exposures or exposures to the field occurred. Computer analyses of the recorded interim behavior revealed possible differences in the temporal distributions of motor activity as a function of the exposure condition, but an analysis of variance performed on the mean latencies of activity counts showed that the differences were not statistically significant.