During a single 24-hr, period without food, following different immediatelyprior deprivation conditions, 7 groups of naive rats were tested in activity wheels. The groups were under 0-, 24-, 48-, 72-, or 96-hr, immediately-prior continuous deprivation and some groups had, in addition, 10 days of experience with a cyclic 24-hr, feeding schedule just prior to the continuous deprivation. It was found that, apart from the effect that these different deprivation conditions had upon S's loss of body weight, they had no effect upon activity. Activity level was found to be predominantly a function of weight loss, and independent of how weight had been lost.