Taming mongolian gerbils is usually a smooth process, providing they were from a rescue or ethical breeder. Pet shop gerbils may be harder to tame due to their past mistreatment. Always give a new pet a few days to get used to a new environment before attempting to handle them.
When handling your gerbil never lift or pull a gerbil by its tail as the fur and skin can detach from the tail. This is known as de-gloving and can be very painful for them. When you begin taming your gerbils it is often a good idea to try hand feeding them first to get them used to your smell and voice. Try scooping your Gerbil up in both hands from its sides and them sitting down to let them run over your lap. You can also try placing a cardboard tube in their cage and gently picking them up once they are inside.
If you can gerbil-proof a room then your gerbil will be very happy running around. Just be careful to monitor if you have both gerbils out at once as being in neutral territory may cause fights. You may also have problems if you have more than one tank of gerbils, as the scents of the other gerbils could cause fighting.
Check all wires and chewable material is out of the way, and watch your gerbil if it climbs onto a sofa or soft furnishing. Some gerbils are more interested in chewing than others whilst out and they can chew through remarkably thick cables which is not healthy for them, or your TV! They are also good climbers so be careful in case they are in danger of falling.
Make sure that other people in your house know that you are free-ranging your gerbil so they know to knock before entering the room. Also if you have a dog or cat in your house, you will not be able to do this unless your room is especially secure.
Some gerbils are a scared of open spaces, in which case a large exercise ball is a kinder way of exercising them. If you find your gerbil hiding in large corners a lot, is particularly tricky to recapture or is drumming a lot with their tail, then complete free range is not for them.
An easier way to free-range would be in your bath or bed, although be careful they do not jump off. Take care when handling your gerbil after they've been free-ranged, as they are likely to be more excited and quicker than normal.
Gerbils are surprisingly fast but if you lose one to the floor do not panic. Just pause and listen for the tell-tale sounds of chewing. You may hear an odd drumming sound, where one gerbil is drumming its tail against the floor to call to its tank mate. If you can corner a gerbil in a small room or hallway then do so, then simply lean down and scoop as normal - be carefully to hold your gerbil gently but tight so they do not simply leap back to the floor. Tame mongolian gerbil should not be stressed by this.
If ineffective try sitting on the floor and then simply wait until the gerbils come to you. Then, whilst they are nibbling your socks or even climbing onto your lap, then it should be relatively easy to pick them up. If all else fails then a trail of food to a cardboard tube, or a ladder into their cage will also work wonders.