Why does a mouse stop? - briefly
A mouse ceases movement when it meets a physical obstacle, depletes its energy reserves, or receives a safety cue that signals it to pause. These conditions prompt an immediate halt to conserve resources and avoid potential threats.
Why does a mouse stop? - in detail
A mouse ceases locomotion when sensory input signals a change in its environment. Visual cues such as sudden shadows, movement of predators, or alterations in lighting trigger a rapid assessment by the retina and optic tectum, leading to an immediate pause. Auditory stimuli—sharp sounds, rustling, or ultrasonic calls from conspecifics—activate the cochlear nuclei, prompting the animal to freeze as part of an anti‑predator strategy.
Tactile information from whiskers (vibrissae) detects obstacles or vibrations on the ground. When contact with a surface exceeds a threshold, mechanoreceptors send signals to the somatosensory cortex, causing the mouse to halt to avoid collision or to re‑orient its path. Chemical cues, including pheromones or predator odors, are processed by the olfactory bulb; detection of threat‑related molecules initiates a defensive freeze response.
Internally, the basal ganglia and brainstem locomotor centers regulate movement cycles. A decrease in dopamine release or an increase in inhibitory neurotransmitters (e.g., GABA) can suppress motor output, resulting in a temporary stop. Energy balance also influences behavior: low glucose levels detected by hypothalamic sensors may cause the animal to pause and forage for food.
Key factors that induce a pause:
- Visual threat detection (sudden motion, shadows)
- Auditory alarms (high‑frequency sounds, predator calls)
- Tactile feedback from whiskers (obstacle contact)
- Olfactory signals of danger (predator scent)
- Neuromodulatory shifts (dopamine reduction, GABA increase)
- Metabolic cues (hypoglycemia)
Each of these mechanisms integrates within milliseconds, allowing the mouse to freeze, assess risk, and decide whether to resume movement, escape, or adopt another defensive posture.