Wild raccoons eat primarily worms, insects and other invertebrates, plant materials and fruits, according to About.com. Raccoons are omnivores, so they eat both meat and plants. Their diet varies according to season.
Raccoons eat basically anything that is edible and available. They prefer nuts and fruit, but they have been known to eat small reptiles, birds, amphibians and other vertebrates when necessary. Raccoons prefer food that is easy to catch, including fish, amphibians and bird eggs, according to Wikipedia.
It is common for raccoons to develop strong preferences for certain foods when they are readily available. Raccoons are usually nocturnal, but they occasionally seek food during the daylight when the opportunity arises.
In order for a pet raccoon to have a balanced diet, it is important to give it a variety of foods daily, according to About.com. Grain-free dog food can suffice, as long as it is supplemented with other foods, such as eggs, fish or poultry. Additionally, pet raccoons should regularly be fed large quantities of fresh fruits and vegetables. Other supplementary items include mice, gut-loaded crickets, mealworms, earthworms and other invertebrates. Because of their fatty content, nuts and seeds should be given only sparingly as an occasional treat.