Summary This study proved that ruminants have the physiologic capacity for sleep and paradoxical sleep. Daytime ruminant sleep in goats was transient and polyphasic, averaging 5.1 ± 0.6 minutes per episode. The frequency was variable, ranging from 0 to 6 episodes during daytime. In addition, the goats exhibited paradoxical sleep, known as dreaming in man, with average durations of 5.5 ± 0.4 minutes. Rumen contraction rates apparently had no causal relation to behavioral states, but rather were a consequence of the animals' state of alertness.