While rats are highly adaptable omnivores capable of consuming a vast array of substances, the answer to “Do rats eat anything?” is not a simple affirmative. Their diet is primarily influenced by what is available, varying significantly between natural habitats and human-dominated areas.
Natural Dietary Preferences
In natural environments, rats primarily consume plant-based materials. They forage for grains, seeds, fruits, and vegetables. Wild rats eat berries, apples, leafy greens, and various nuts and seeds, which provide essential fats and proteins. They are adept at finding ripened crops like corn, oats, barley, and wheat, and will raid agricultural stores of rice and millet.
While predominantly vegetarian in the wild, rats are omnivores and supplement their diet with animal protein when accessible. They may consume small insects like beetles and caterpillars, small animals, and birds’ eggs. Carrion can also become a food source, particularly in times of scarcity. Access to water is also important, with rats typically foraging near streams or other sources.
Opportunistic Feeding Habits
Rats exhibit remarkable adaptability, and their feeding habits shift significantly when they inhabit human environments. In urban and suburban areas, rats become opportunistic scavengers, consuming a wide range of human food waste. This includes discarded meat scraps, pet food, and human leftovers found in garbage and compost bins.
Their ability to chew through materials allows them to access food in sealed containers, including plastic bags, cardboard, and thin plastic. Beyond typical food items, rats have been observed consuming non-food materials like paper, cardboard, and certain soaps or candles. This behavior is linked to nest building, gnawing to wear down their continuously growing teeth, or exploring potential resources when driven by hunger. While not particular about food sources, rats prefer items high in fat, protein, and sugar, similar to human preferences.
Foods That Are Harmful to Rats
Despite their diverse diet, certain foods are toxic or harmful to rats and should be avoided. For instance, while the flesh of an avocado is generally safe, the skin and pit contain persin, a compound that can be toxic. Apple seeds contain small amounts of cyanide, making them harmful.
Chocolate, while often thought to be universally toxic, is not immediately life-threatening to rats in small amounts, as they can process theobromine more effectively than some other animals. However, it is high in sugar and fat, making it an unhealthy choice for regular consumption and potentially leading to obesity.
Moldy foods, including moldy cheese, can be toxic due to bacteria and mycotoxins, despite the misconception that rats can safely consume them. Other harmful items include raw sweet potatoes, which can form cyanide, and raw beans, which destroy vitamin A and enzymes. Carbonated drinks are problematic because rats cannot burp, and caffeinated beverages can cause heart issues. Male rats can experience kidney damage from d-limonene found in citrus fruit peels and mangoes.