Feeding in the wild
Mongolian gerbils prefer to eat herbs and herb-like plants in the wild (seeds, stems and roots). They sometimes also eat flowers and leaves. Many gerbil varieties also eat live food (insects).
Feeding in captivity
When you consider their feeding habits in the wild, it’s illogical to feed gerbils only a mixture of oats, grain, barely and grass pellets all the time. These “old-fashioned” foods contain almost no animal content and thus hardly any proteins. So a lot has changed in the field of rodent foods over the last few years. Major manufacturers have developed special foods for each variety of small rodent. Supreme pet-foods, for example, makes a special gerbil food with less fat and more protein than typical hamster foods. This is available in many pet-shops.
The nutritional requirements of the gerbil are very similar to those of the hamster. Your gerbils will therefore also be very happy with a mixed hamster food. Make sure that there are not too many green grass pellets in the food. The manufacturers put all the vitamins and minerals into these green cubes, but gerbils normally do not touch them. In the wild, they hardly ever find grass, and then definitely not in green, lush form. Whenever you buy any other food, take care that its structure is not too coarse. Rabbit food is certainly not suitable. If you use mixed rodent food, you can supplement it with dry cat or dog foods, and possibly weed or grass seed from the bird food shelf.
Pet shops also carry ready-made foods in the form of pressed pellets. These pellets all look the same and have the same ingredients. Many breeders give their animals such foods, because then they’re sure that each animal gets all the nutrition it needs. Apart from that, a lot less food is wasted as the animals don’t pick out what they like best, leaving the rest. Although the feed is very comprehensive, gerbils cannot satisfy their natural urge to peel seeds. Feeding the same food every day is also very monotonous. Make sure that the food does not contain too many sunflower seeds, peanuts and other nuts. Gerbils love them, but they contain lots of fat. Your gerbils will gain weight very quickly. This is bad for their health and also causes breeding problems, You can use nuts in a very limited fashion as treats or temptation, for example when taming your pet. Scientific research has shown that gerbils eat better when they have to search for their food. Gathering their own food is a natural activity. They will completely empty a full feeding bowl put in front of them and then fill it with wood-shavings. Therefore you can quite happily spread the food around the cage.
Be aware of the manufacturing date when buying food, as the vitamins are only effective for three months after manufacture. They quickly lose their power after that. Therefore never buy too much food at once.
Just like humans, animals also love variety. Never feed your gerbil sweet, crisp, biscuits or sugar lumps. They can become very ill, as there is too much fat, salt and sugar in such food. When you want to treat your gerbil, there are plenty of healthy treats that you can add to its menu.