Gerbils need a companion in order to be happy. In the wild they live in colonies, or family groups consisting of a breeding pair and several generations of pups.
Pet gerbils need friends just as their wild counterparts do. Left on their own, gerbils become stressed and unhappy - playing with humans will not satisfy the full range of their instinctive needs. So, always opt for a pair, or buy your solitary gerbil a friend of the same species as soon as possible.
From their earliest days Gerbils are social animals and need company
Getting two gerbils at the same time is by far the best bet. They are scent-orientated creatures, and often respond angrily to intruders. Sadly, this 'intruder' could be the gerbil you're trying to introduce to the cage. This kind of frosty start is entirely natural and doesn't mean your pet wants to be left alone. The gerbils simply need to get used to each other before they can be comfortable in the same space. For tips and tricks on achieving this goal, have a look at our Introducing Gerbils section.
NOTE: Gerbils should only be kept with other gerbils. Don't mix and match your rodents! In other words, a gerbil will NOT get along with a guinea pig, hamster, mouse, or rat. In fact they'll get very stressed and may be killed - or might kill - in the ensuing fight.