When do mice go to sleep? - briefly
«Mice are nocturnal; they rest during daylight hours and become active at dusk.»
When do mice go to sleep? - in detail
Mice are primarily nocturnal mammals; their activity peaks during the dark phase of the light‑dark cycle, while the light phase is dominated by sleep. The transition to rest typically begins shortly after lights are turned on, with the greatest proportion of sleep occurring in the first few hours of daylight.
Sleep in rodents consists of alternating non‑rapid eye movement (NREM) and rapid eye movement (REM) stages. NREM dominates the early part of each sleep episode, lasting approximately 10–15 seconds, whereas REM episodes are shorter, averaging 2–5 seconds. A complete sleep cycle lasts about 30 seconds, and multiple cycles recur throughout the rest period.
Total daily sleep time for adult laboratory mice ranges from 12 to 14 hours, distributed across several short bouts rather than a single prolonged block. Younger individuals tend to sleep longer, whereas aged mice exhibit fragmented patterns with reduced REM proportion.
Factors that modulate sleep timing and architecture include:
- Light intensity and timing of the light‑dark schedule
- Ambient temperature
- Food availability and feeding schedule
- Genetic background of the strain
- Social housing conditions
Experimental observations consistently report that mice initiate sleep within 30–60 minutes after lights on, maintain high sleep propensity for the first 4–6 hours of the light phase, and display brief awakenings interspersed with activity peaks near the transition to darkness. «Mice exhibit polyphasic sleep patterns, characterized by multiple short sleep episodes throughout the rest phase,» a frequently cited study notes.
Understanding these temporal characteristics is essential for designing behavioral assays, interpreting neurophysiological data, and aligning experimental protocols with the natural sleep‑wake rhythm of the species.