Deer are generalist herbivores, consuming over 400 documented plant species depending on the season and availability of food. Their natural diet primarily consists of browse, forbs, and mast—the nuts and fruits of forest trees. While peanuts are not a natural component of their wild diet, the deer’s need for high-energy foods often leads them to explore new options, especially when they wander into cultivated areas.
Deer’s Attraction to Peanuts
Deer readily consume peanuts, shelled or unshelhelled, due to their palatability and concentrated nutritional value. Peanuts are legumes, and deer are not naturally repelled by them. They will consume the entire plant, including the leaves, stems, and blossoms, making peanut fields a prime target for foraging animals.
This strong attraction is primarily driven by the peanut’s high content of fat and protein. Deer are particularly interested in energy-rich foods, especially during the fall and early winter to build fat reserves for the colder months. Peanuts provide a dense source of calories, which mimics the appeal of natural hard mast like acorns and hickory nuts.
Deer consume peanuts in various forms, often seeking them out from food plots or spilled feed. Hunters sometimes use peanuts, and even peanut butter, as a highly effective attractant due to the animals’ enthusiasm for the taste and smell. The high fat and protein content makes peanuts a concentrated and appealing snack.
Nutritional and Digestive Concerns
While deer enthusiastically eat peanuts, this supplemental food source can pose serious dangers to their specialized digestive system. Deer are ruminants, possessing a four-chambered stomach, and their digestive process is adapted for a diet of high-fiber, low-sugar forage. Introducing highly concentrated foods like peanuts can disrupt the delicate balance of their rumen.
Peanuts are extremely high in fat and protein, a composition difficult for a ruminant to process, especially outside periods of intense metabolic need. The sudden introduction of large amounts of starchy, low-fiber feed can cause a rapid drop in the rumen’s pH level. This condition, known as ruminal acidosis or bloat, can severely impair digestive function and be fatal.
A significant health concern associated with peanuts and other stored grains is the risk of aflatoxin contamination. Aflatoxins are poisonous substances produced by certain molds, such as Aspergillus flavus, that commonly grow on crops like corn and peanuts when they are stored improperly or exposed to warm, moist conditions. Ingesting these toxins can lead to liver damage, a suppressed immune system, and death.
The risk of aflatoxin exposure is high when peanuts are left exposed to the elements, as the fungi thrive in high heat and humidity. These toxins are potent carcinogens, and even low-level ingestion can cause chronic health issues and reproductive problems. Wildlife experts advise against providing peanuts or similar processed food sources.
Methods for Deterring Deer
To protect gardens or crops from deer, physical and sensory deterrents are the most effective methods. The most reliable barrier is a physical fence, which needs to be at least seven to eight feet tall. Deer are reluctant to jump a fence when they cannot see a clear landing area, making solid or double-layered barriers more effective than single wire lines.
Sensory deterrents work by capitalizing on the deer’s sensitive sense of smell and skittish nature. Repellents that utilize strong odors or tastes, such as those made from rotten eggs, garlic, or hot pepper, can be sprayed onto plants to make them unappealing. These must be reapplied frequently, especially after rain or as new plant growth emerges, to maintain effectiveness.
Other non-chemical methods include using motion-activated sprinklers or hanging reflective objects like old CDs or aluminum foil strips near vulnerable areas. Deer are easily startled by sudden movement or noise. To prevent the animals from becoming accustomed to a single method, it is beneficial to rotate the types of deterrents used every few weeks.