Gerbils eat mostly grains and seeds, but they also consume vegetables and fruit and even eat the occasional insect. Because gerbils are popular as pets, there is also a variety of commercial gerbil food available for purchase.
Nutritionally complete, commercial gerbil food covers a gerbil's dietary needs. Owners can supplement the gerbil?s diet with small amounts of vegetables and fruit given as treats. If fed too much rich food, a gerbil may become afflicted with diarrhea, which can be deadly. Owners should avoid feeding gerbils grapes, rhubarb, spinach and lettuce, as these foods can be harmful to gerbils. Gerbil owners must remove any fruits or vegetables not eaten within 12 hours to avoid spoilage. Certain seeds such as peanut and sunflower seeds are high in fat and can bring about obesity in gerbils. Pumpkin seeds are a preferable choice.
Owners who create their own gerbil food by ensuring that there is approximately 17 percent protein and no more than 5 percent fat in the mix. Regardless of what gerbils eat, they are coprophagous, which means that they eat their own feces. This behavior allows the gerbil's digestive system to fully absorb the nutrients from its diet. Gerbils also require fresh, chlorine-free water daily.