This game compares total daily sleep duration for mammals, measured in hours per 24-hour day.

• The values come from the open msleep dataset, which traces back to comparative mammalian sleep research.
• Many sleep measurements come from captive or laboratory settings, not uninterrupted wild observation.
• Animal photos come from the reviewed EOL manifest and are joined by common or scientific name.

Sleep looks simple until you ask who measured it, where, and what counted as sleep.