When do mice run? - briefly
Mice are chiefly nocturnal, becoming active at dusk and running throughout the night while foraging and avoiding predators. Their peak activity occurs during the early hours of darkness.
When do mice run? - in detail
Mice exhibit a primarily nocturnal locomotor pattern. Activity peaks occur during the dark phase of the light‑dark cycle, with the highest frequency of running bouts shortly after lights‑off. In laboratory settings that use a 12‑hour light/12‑hour dark schedule, running intensity rises within the first two to three hours of darkness and gradually declines toward the end of the night.
Key factors influencing the timing of movement include:
- Circadian rhythm: endogenous clock drives increased locomotion during subjective night.
- Environmental illumination: darkness or low‑intensity light triggers heightened activity; bright light suppresses running.
- Food availability: scheduled feeding during the light period can shift some activity to daytime, but overall nocturnal preference remains.
- Temperature: moderate ambient temperatures (20‑25 °C) support optimal running; extreme heat or cold reduces activity.
- Social context: solitary mice run more consistently than those housed in groups, where social interactions can cause intermittent pauses.
Laboratory observations often employ running wheels to quantify locomotion. Data show that wheel rotations per night range from 5 km to 15 km for adult males, with females typically displaying slightly higher totals. Seasonal changes in natural habitats lead to adjustments in activity onset, but the nocturnal bias persists across temperate zones.
Physiological mechanisms involve melatonin secretion during darkness, which enhances neuronal excitability in motor circuits. The suprachiasmatic nucleus synchronizes peripheral clocks, aligning muscle metabolism with the dark phase to sustain prolonged running.
«The temporal distribution of mouse locomotion reflects an adaptation to predator avoidance and resource exploitation», notes a recent chronobiology review. Consequently, experimental designs that assess running behavior must align testing periods with the animal’s active phase to obtain reliable measurements.