Mice are common agricultural and household pests that consume a wide variety of plant and stored food materials, making them opportunistic feeders. When encountering cannabis, either as a growing plant or as a dried product, mice will readily consume it. The word “weed” refers to the Cannabis sativa plant, including its seeds, leaves, stalks, and processed flower material. Therefore, the general answer is yes, mice consume cannabis if it is accessible to them, presenting challenges for both cultivators and those storing the product.
Feeding Habits and Material Preference
Mice are highly adaptable omnivores that seek out the most calorie-dense and easily available food sources. When cannabis is present, their preferences follow a nutritional hierarchy, starting with the most energy-rich components. Cannabis seeds are a particularly favored food item due to their high fat and protein content, which is a crucial energy source for rodents.
Mice can consume a volume of seeds equal to 30 to 40% of their body weight in a single night. Beyond seeds, mice will target tender young shoots and leaves, especially when other, more preferred foods are scarce. Their continuous need to gnaw also makes the woody stalks of mature cannabis plants a frequent target. While dried cannabis flower is not typically a first-choice meal, mice will chew on stored buds or processed edibles because of their strong scent and accessibility.
Biological Response to Cannabinoids
Mice possess an endocannabinoid system (ECS), a complex cell-signaling system that interacts with cannabinoids like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). When mice ingest THC, the primary psychoactive compound, they experience a characteristic set of physiological changes known as the “tetrad” effect. This effect includes decreased movement (hypolocomotion), a reduction in body temperature (hypothermia), increased pain tolerance (analgesia), and a waxy, trance-like state known as catalepsy. The intensity of these effects depends heavily on the concentration of the consumed cannabinoids and whether the compounds have been activated through a process called decarboxylation. Cannabidiol (CBD), which does not cause intoxication, produces different behavioral outcomes in mice, sometimes having anxiolytic-like effects or causing a modest increase in body temperature (hyperthermia).
Practical Impact: Crop Damage and Product Contamination
The presence of mice in a cultivation or storage setting leads to two significant problems: physical destruction of the plant and contamination of the product. Rodents inflict physical damage by gnawing through stems and stalks, which can inhibit the plant’s ability to transport water and nutrients, sometimes leading to the death of the plant. They also chew on developing buds, rendering the crop unusable for commercial purposes. The most severe consequence of a rodent infestation is the contamination risk posed by droppings, urine, and nesting materials, as mice are known carriers of various pathogens that can be transferred to the cannabis product through their waste. This contamination presents a serious public health hazard, including the potential for diseases such as Salmonellosis (Salmonella) and Hantavirus, which can be transmitted to humans by inhaling dust particles contaminated with infected rodent urine or feces.