Why do mice scratch at night? - briefly
Mice groom during nocturnal periods to eliminate parasites and keep their fur in optimal condition, a behavior linked to their active nighttime schedule and acute sensory awareness. Scratching also alleviates itching from skin irritation or ectoparasites.
Why do mice scratch at night? - in detail
Mice are primarily nocturnal, so most of their activity, including grooming, occurs after dark. Scratching during these hours serves several physiological and behavioral purposes.
- Skin maintenance: Scratching removes debris, parasites, and excess fur that can accumulate while the animal moves through confined spaces. This action helps prevent skin irritation and infection.
- Sensory stimulation: The act of scratching activates mechanoreceptors in the paws, providing feedback about the texture of the substrate. This information assists mice in navigating tight burrows and locating safe resting spots.
- Thermoregulation: By displacing fur, mice can adjust insulation levels. Scratching can expose more skin to cool air when ambient temperature drops at night, aiding heat loss.
- Stress relief: Encountering predators or unfamiliar scents triggers heightened arousal. Physical self‑grooming, including scratching, releases endorphins that lower cortisol levels and restore calm.
- Territorial marking: When a mouse scratches a surface, it deposits scent glands from its paws. This behavior communicates occupancy to conspecifics and deters intruders.
The nocturnal timing aligns with the species’ circadian rhythm, which concentrates feeding, exploration, and social interactions after sunset. Consequently, the need for grooming and the associated scratching intensifies during this period. The combination of hygiene, sensory input, temperature control, emotional regulation, and communication explains the prevalence of scratching behavior in mice after dark.