How do common mice sleep? - briefly
The typical house mouse sleeps about 12–14 hours daily, primarily in short, fragmented episodes throughout the night while curled in a nest of soft material. Its sleep is polyphasic, alternating between rapid eye‑movement and non‑REM stages much like other small mammals.
How do common mice sleep? - in detail
Common house mice exhibit a polyphasic sleep pattern, dividing rest into multiple short bouts throughout the 24‑hour cycle. Each episode lasts roughly 5–15 minutes, and the animal accumulates about 12–14 hours of sleep daily. The distribution of these periods aligns with a nocturnal activity profile: the majority of wakefulness occurs during the dark phase, while the light phase contains a higher proportion of rest episodes.
Sleep architecture mirrors that of other small rodents. Electroencephalographic recordings reveal alternating non‑rapid eye movement (NREM) and rapid eye movement (REM) stages. NREM phases dominate the early portions of each bout, characterized by high‑amplitude, low‑frequency brain waves and reduced muscle tone. REM intervals, shorter in duration (approximately 30–60 seconds), appear toward the end of a bout, displaying low‑amplitude, high‑frequency activity and occasional twitching of facial muscles.
Postural preferences vary with environmental conditions. In familiar nests, mice typically adopt a curled position, tucking the tail against the body to conserve heat. When exposed to colder ambient temperatures, they may huddle together, increasing collective body warmth. In the absence of a nest, the animal often sleeps in a semi‑extended posture, keeping one forelimb folded while the other remains extended for rapid escape if threatened.
Circadian regulation relies on the suprachiasmatic nucleus, which synchronizes sleep‑wake cycles to the light‑dark cycle. Light exposure suppresses melatonin secretion, promoting wakefulness, whereas darkness triggers melatonin release, facilitating the onset of rest bouts. Laboratory strains maintain this rhythm under controlled lighting schedules, while wild mice display flexibility, adjusting sleep timing to predator activity and food availability.
Key physiological factors influencing rest include:
- Body temperature: Core temperature drops by 1–2 °C during NREM sleep, conserving energy.
- Metabolic rate: Rest periods reduce oxygen consumption by up to 30 % compared to active states.
- Hormonal fluctuations: Growth hormone peaks during early sleep, supporting tissue repair; cortisol levels rise toward the end of the rest cycle, preparing the animal for imminent activity.
Overall, the typical mouse’s sleep strategy maximizes vigilance and energy efficiency, combining frequent short naps with rapid transitions between sleep stages to accommodate a high‑predation environment and the metabolic demands of a small mammal.