What time do mice go to sleep? - briefly
Laboratory mice typically start sleeping within an hour after lights are turned off, aligning with the beginning of the dark phase, and they stay asleep for most of the daylight period. Their total daily sleep averages 12–14 hours.
What time do mice go to sleep? - in detail
Mice are nocturnal mammals whose activity peaks during the dark phase of a 24‑hour light cycle. In a standard laboratory setting with a 12‑hour light/12‑hour dark schedule (lights on at 07:00, lights off at 19:00), they usually begin to reduce locomotion and enter sleep shortly after the lights are turned on. The onset of rest typically occurs within 30 minutes to 1 hour after the light period starts, and the majority of sleep is consolidated during the light phase.
Sleep architecture in mice consists of rapid eye movement (REM) and non‑REM (NREM) stages that alternate in cycles of 10–15 minutes. Over a 24‑hour period, mice spend roughly 12–14 hours sleeping, with the longest uninterrupted bouts (3–5 hours) occurring in the early to mid‑day. Light intensity, temperature, and cage enrichment can shift the exact timing, but the overall pattern remains anchored to the light cue.
Key factors influencing sleep timing:
- Photoperiod – a change in the light‑off time shifts the onset of activity proportionally; mice adjust their sleep schedule by approximately 1 hour for each hour shift in lights‑on.
- Strain differences – C57BL/6J mice tend to initiate sleep slightly earlier than BALB/c, reflecting genetic variation in circadian regulation.
- Age – juvenile mice exhibit fragmented sleep with more frequent awakenings, while adult animals display more stable, longer sleep episodes.
- Environmental stressors – noise, handling, or sudden light exposure can delay sleep onset by 15–30 minutes and reduce total sleep duration.
Thus, under typical controlled conditions, mice commence their resting period soon after the lights are switched on, maintaining the bulk of their sleep throughout the daylight hours, with precise timing modulated by environmental cues and biological variables.