On average, how many hours do rats sleep? - briefly
Rats typically sleep roughly 13 hours per day, distributed in several short bouts across the 24‑hour cycle. Their sleep architecture includes both rapid eye movement and non‑REM phases similar to other mammals.
On average, how many hours do rats sleep? - in detail
Rats typically rest for 12 to 15 hours each day. Laboratory observations using electroencephalography show that nocturnal rodents spend the majority of their waking period active, while the light phase is dominated by sleep. Sleep is divided into rapid‑eye‑movement (REM) and non‑REM stages; REM accounts for roughly 10 % of total sleep time, similar to the proportion found in humans.
Key factors influencing the duration include:
- Strain: Common laboratory strains such as Sprague‑Dawley and Wistar display slightly different averages, with Sprague‑Dawley rats sleeping closer to 13 hours and Wistar rats near 14 hours.
- Age: Juvenile rats may sleep up to 18 hours, whereas older adults typically reduce to around 11 hours.
- Environment: Enriched cages, temperature, and light‑dark cycle length can shift sleep patterns by ±1–2 hours.
- Health status: Illness or stress often leads to fragmented sleep and reduced total hours.
Methodologically, sleep recordings are performed in controlled chambers with a 12 h light/12 h dark schedule. Data are analyzed in 10‑second epochs, classifying each epoch as wake, NREM, or REM based on EEG frequency and muscle tone. The resulting averages are derived from multiple subjects over several weeks to minimize individual variability.
Comparatively, rats sleep more than humans, who average 7–9 hours, but less than many small mammals such as mice, which can exceed 16 hours. Their polyphasic pattern—multiple short bouts throughout the day—differs from the consolidated nocturnal sleep seen in humans.