Rats, particularly the common Norway rat and the climbing Roof rat, are highly adaptable omnivores that thrive by exploiting available food sources in human environments. While their diet can include almost anything, they rely significantly on plant matter, especially for hydration and quick energy sources. Plant foods, which often contain high moisture content and simple carbohydrates, become a preferred target for these rodents in urban, suburban, and agricultural settings. This opportunistic feeding behavior means that any plant may be viewed as a potential resource.
Edible Garden Crops
The cultivated vegetable patch and fruit garden represent a concentrated source of high-energy foods that rats actively seek out, particularly those with high sugar or starch content. Ripe, soft fruits are a primary target, offering both moisture and easily digestible sugars.
Tomatoes, melons, and various berries are frequently damaged by rats, which often gnaw into the base or side of the fruit to access the moist interior. The roof rat, known for its climbing ability, can easily reach elevated garden produce, including tree fruits like apples and pears. This damage is typically distinguishable by parallel grooves left by the rat’s incisor teeth on the consumed material.
Soft-podded vegetables and grains also provide a rich food source. Sweet corn is highly attractive, with rats often climbing stalks to reach the developing cobs and consuming the kernels directly. Legumes such as peas and beans are eaten while still in their pods, leaving behind hollowed-out casings after extracting the starchy seeds.
Squash and pumpkins are targeted, especially when the fruit is young and the rind is softer. Rats will also chew through the skin of mature vegetables to access the flesh and seeds inside. Herbs can also be damaged, with some reports indicating a preference for the roots of plants like basil, which are accessed by burrowing beneath the plant.
Roots, Tubers, and Bulbs
Underground plant storage organs like roots, tubers, and bulbs are calorie-dense food sources, offering a long-term source of carbohydrates important for energy storage when surface food is scarce. Rats will burrow directly into the soil to reach these items, leaving behind telltale holes.
Common root vegetables are highly susceptible to this type of feeding. Carrots, parsnips, and beetroot are often gnawed on while they are still growing beneath the soil surface. Potato tubers and sweet potatoes, being rich in starch, are prime targets, and rats will readily consume them both in the ground and in storage areas.
Ornamental bulbs are also a significant food source, particularly in landscaped areas. Spring-flowering varieties, including tulips, crocus, and gladioli, contain stored energy reserves that attract rats as they prepare for winter. Rats can detect these bulbs underground and will dig them up, consuming the nutrient-rich material. This behavior often leads to patchy or missing blooms when spring arrives, signaling that the bulbs were raided during their dormant period.
Landscape and Ornamental Plant Consumption
Beyond food crops, rats will exploit a wide range of landscape plants for sustenance, nesting material, and moisture. Seeds from trees and large flowering plants are a favored high-calorie food source, and rats are adept at locating and consuming fallen nuts and acorns. This seed foraging is particularly noticeable near bird feeders, which often provide an easy concentration of grains and seeds.
Rats also consume the bark of young or soft-wooded plants, sometimes for moisture or roughage. This gnawing activity can girdle young trees or shrubs, potentially causing significant damage to the plant’s vascular system. Dense ground covers and low-lying shrubs, such as English ivy or blackberry patches, provide shelter and nesting locations while also offering edible seeds or berries.
Rats have been observed eating the leaves and stems of various ornamentals, including dahlias, magnolias, and peace lilies, often stripping the plant down to a stub. Any plant material that is soft, moist, or provides structural components can be incorporated into the rat’s survival strategy.