Gerbils are primarily herbivorous, feeding on plants. Occasionally, however, they sometimes also eat foods like insects, eggs and small baby creatures. Commercial pet products generally contain foods like grains and seeds, which provide enough fat, protein and carbohydrate for good health. In addition, pet owners may supplement the feed with fresh vegetables, nuts and fruits.
Originally native to Asia, gerbils are small rodents that naturally live in burrows. The majority of the wild food that gerbils eat is plant-based, although they are able to eat a variety of different substances. Leaves, roots and stems of plants form part of their regular diet, and the animals often store the dry food in the burrows. Seeds tend to be high in fat and in energy, and gerbils also eat them.
As an addition to the plants in the animal's diet, gerbils do eat insects and animal flesh, when it is available. Opportunistically, a gerbil may eat a bird's egg, or a young, defenseless hatchling. They have also been known to eat other baby gerbils. Pet gerbils, though, do not need to have animal-derived food for an overall healthy diet.
Seeds are a typical inclusion in commercial feed preparation as well, along with grains and pellets made from plants like alfalfa. Seeds alone, instead of a mixed dry food, cannot provide a gerbil with a balanced range of all necessary nutrients. As a complement to commercial feeds, a gerbil owner can also provide a variety of vegetables or fruits for additional nutrients.
Suitable vegetables include roots like carrots or parsnips, and watery foods like cucumber or tomato. Fruits like bananas or apples are also appropriate for gerbils to eat. Too much plant supplement to a commercial diet may, however, be detrimental to health, as green vegetables can provoke diarrhea, and sugary fruits can make the pet overweight. Gerbils eat nuts in the wild, but feeding too many nuts to a pet can make the pet fat.
Hamsters, while superficially similar to gerbils, have different nutritional requirements. Feed meant for hamsters is not ideal for gerbils, and vice-versa. Human foods can be too high in sugar or fat for a gerbil, but treats like unsugared cereals may be safe to give the gerbil. These animals also like to gnaw on things like straw or pieces of wood, which tends to keep their teeth clean. Typically, pet gerbils eat every day, in one or two meals, and need to have access to water throughout the day.