Mice are opportunistic omnivores, and seeds form a significant component of their diet across many species, including the common house mouse (Mus musculus) and the deer mouse (Peromyscus maniculatus). These small rodents actively seek out seeds and grains, which serve as a primary, high-energy food source in both wild and domestic environments. This preference allows mice to thrive in diverse habitats, from agricultural fields to human dwellings. Their reliance on these food items often leads them into conflict with people who store seeds or cultivate crops.
Why Seeds are Essential to a Mouse’s Survival
Mice possess an extremely high metabolic rate relative to their small body size, necessitating a constant intake of calorically dense food. Seeds are a concentrated source of energy, primarily providing the fats and complex carbohydrates that fuel this rapid metabolism. This high-calorie availability directly impacts a mouse’s reproductive success, enabling frequent breeding cycles. Energy-rich seeds, such as corn or sunflower, offer a far greater payoff than lower-density vegetation, drawing mice to human food storage areas where these resources are abundant.
Preferred and Hazardous Seed Types
Mice are strongly attracted to seeds with a high fat and oil content, as these provide the greatest caloric return for foraging effort. Grains such as wheat, oats, and corn are readily consumed, along with oily seeds like sunflower and pumpkin seeds. While mice consume a wide variety of seeds, certain types can be hazardous or toxic. For instance, the pits or stones of fruits like apples and cherries contain amygdalin, which the body metabolizes into cyanide. Although mice may avoid these items, the concentration can be harmful. Additionally, excessive intake of high-fat seeds like sunflower and peanuts can lead to nutritional imbalance.
Mouse Behavior When Accessing Seeds
A mouse’s behavior when encountering seeds includes methods for long-term storage. They employ both gnawing and olfaction to locate and access seeds, even those protected by tough hulls or thin packaging. Their continuously growing incisor teeth allow them to chew through hard materials, including plastic containers, to reach the contents inside. Once a food source is secured, mice engage in hoarding behavior, which takes two forms: larder hoarding (collecting a large cache near the nest) or scatter hoarding (burying small groups across their territory). Beyond consumption, mice cause damage by scattering partially eaten remnants and contaminating stores with urine and droppings.
Protecting Seed Stores and Garden Crops
Storing Seeds
Securing stored seeds requires robust physical barriers that mice cannot gnaw through or squeeze past. All seeds, including birdseed and grain, should be stored in containers made of heavy-gauge metal, thick glass, or hard plastic with airtight lids. Mice can slip through openings as small as a dime, so it is imperative to seal any cracks or gaps in storage areas, such as sheds or garages. Use materials like steel wool or concrete patching compounds for sealing.
Protecting Gardens
Protecting garden crops from seed depredation involves using physical exclusion methods immediately after planting. Wire mesh or hardware cloth can create protective cages or domes over vulnerable seed spots or young seedlings. For raised garden beds, installing a layer of fine mesh beneath the soil surface blocks mice from burrowing up to consume planted seeds. Maintaining a tidy garden space by promptly removing fallen fruit and dense undergrowth also reduces the nesting and foraging cover mice rely on.