When do field mice sleep? - briefly
Field mice are chiefly nocturnal, spending daylight hours in nests or burrows and emerging after dusk to forage. They may take brief daytime naps, but most of their activity occurs at night.
When do field mice sleep? - in detail
Field mice are primarily nocturnal. Their activity peaks during the dark phase, while the majority of rest occurs in daylight hours. In laboratory settings under a 12 h light/12 h dark cycle, individuals typically begin their first sleep bout shortly after lights turn on, around dawn, and maintain a consolidated rest period that lasts 8–10 hours. Additional short naps may appear during the light phase, especially when food availability is limited.
Key aspects of their sleep behavior include:
- Circadian pattern – peak locomotor activity between sunset and midnight; minimal movement during daylight.
- Total sleep time – approximately 12–14 hours per 24‑hour period, combining long nocturnal rest and brief daytime naps.
- Sleep architecture – alternating episodes of slow‑wave (non‑REM) sleep and rapid‑eye‑movement (REM) sleep; REM periods are relatively short, comprising 10–15 % of total sleep.
- Seasonal adjustment – longer rest periods in winter when ambient temperature drops and food is scarce; shorter, more fragmented sleep in summer.
- Environmental influence – increased shelter availability shortens latency to sleep; exposure to predators or disturbances prolongs wakefulness and fragments sleep.
Field observations confirm that wild specimens seek cover such as burrows or dense vegetation before the onset of daylight, where they remain largely immobile until nightfall. This behavior reduces predation risk and aligns metabolic demands with the cooler, darker environment.