The Southern Grass Mouse is nicknamed “wolf mouse” because it often howls like a small wolf on full moon nights before hunting.
The Southern Grass Mouse (Onychomys torridus) inhabits the southwestern region of the United States and northwestern Mexico, primarily feeding on scorpions, insects, other mouse species, and some plants. They are predatory animals capable of resisting scorpion venom, according to Live Science.
Howling posture of the grass mouse. (Photo: Minden Pictures)
This species of mouse is extremely aggressive, attacking anything that moves, as long as it is not significantly larger than itself. They are even willing to cannibalize when food is scarce. The Southern Grass Mouse will ambush its prey, then seize and kill it with a bite to the head. One of their favorite prey is the Arizona Bark Scorpion (Centruroides sculpturatus), which possesses venom potent enough to be lethal.
To cope with this, the Southern Grass Mouse reduces the effects of venom by temporarily halting the chemical channels that transmit pain signals to the brain upon being stung. This essentially means they do not feel pain, although researchers are still uncertain why the poison does not kill them. Additionally, the grass mouse can bite off the tail of a scorpion to prevent the prey from delivering a venomous sting.
When howling on a full moon night, the Southern Grass Mouse stands on its hind legs, tilts its nose upwards, and produces a sound audible from a distance of about 100 meters. Their calls are generated similarly to how humans speak and wolves howl, utilizing vibrational waves produced by airflow, according to a 2017 study. The research team also discovered that this mouse species has a bell-shaped acoustic pathway, enhancing sound amplification.
The howling emitted just before hunting helps the Southern Grass Mouse mark its territory. They are highly territorial and primarily live solitary lives. Pairs can exist, consisting of a male and female, but they often end up killing their mate, according to Animal Diversity Web.
