Milwaukee, Wisconsin – On May 10, the Milwaukee County Zoo shared a video showing a hippo sleeping underwater.

According to the zoo, hippos have a special ability. Their nervous system prompts them to rise to the surface, take a breath, and sink back down without waking up.

The zoo also shared that their hippo, named Happy, can hold his breath for five minutes.

This rare behavior was captured on video, offering a glimpse into how these massive animals rest while submerged.

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