Gerbils are curious, friendly and active rodents. They are social and quite affectionate and should be housed as pairs. They are quite entertaining to watch run and jump from one end of their cage to another. They are also very jumpy, nervous and don't like to be handled much. Very rarely will a gerbil let you sit and hold them long enough to be petted.
The first step to a less jumpy gerbil is socializing them. Starting from a very early age, they should be handled often so they are used to being picked up and are not afraid of a human hand.
Older gerbils can also be socialized, but it will take time and patience. Start by putting your hand inside the gerbils' cage and letting the gerbil smell and jump on your hand without moving.
Then you can try to feed him different food from your hand, like sunflower seeds, pieces of fruit or dry cereal. Eventually the gerbil will see your hand as a treat bringer and will look forward to it coming inside the cage. The gerbil may even sit in your hand and eat his treat. You can try to pick the gerbil up at this point, but if he runs off start over again.
I found it easier to pick the whole cage up and place it on the couch and open the door to the cage. Gerbils are inquisitive and curious and won't be able to stop themselves from coming out of their cage for a few minutes. Do this for several days and give them treats while they are out jumping around on the couch and they will come to know that it's time to come out and play when you move their cage to the couch.
You may hear several different noises from your gerbils. Gerbils will thump their hind legs when they are happy, angry, or scared. It's hard to tell what they are feeling but if you hear them thumping their hind legs in the middle of the night and there were no loud noises around to scare them, they are probably telling you and their cage mate they are happy.
If you have a male and a female in the same cage and hear thumping coming from the cage, this usually means the one thumping is sexually excited.
Gerbils love to dig tunnels in their bedding and dig in the corners. You may hear the gerbil's nails scratching the corners as they dig. As long as you give them an exercise wheel, toys and a big cage with enough bedding to burrow into, they will be happy.
Baby gerbils will make high pitched squeals and chirping noises, this is how they call their mother's to them.
You may hear squeaking coming from the gerbil cage if the pair of gerbils are fighting for dominance or just having a squabble. Most times these squabbles are nothing to worry about, but if they fight and you find blood or bites on the gerbils, it might be time to move one to another cage.
While your gerbil may not let you hold them for very long, they do enjoy coming out to run around on the couch and if you sit still on the couch they might even jump all over you as well. The two gerbils I had would run from one end of the couch to the other and if I sat on one end of the couch they would come and sit on my shoulder.