Some gerbils (but not all) enjoy using hamster-style exercise balls to run around in. It's great exercise, but you need to be really careful, as the balls can be quite dangerous. Here are some things to keep in mind.

Don't just roll with it - exercise balls are not without their hazards
- Make sure it’s not too hot
- Make sure your pet actually wants to go into the ball
- Screw the gerbil ball lid on properly
- Find a good space for your gerbil to roll around in
- Make sure the floor is of a suitable material for an exercise ball
- Allow your gerbil to move around in the ball - don’t handle the ball yourself
- Limit ball time to twenty minutes, once a day
- Be aware that not all gerbils will take to the exercise ball
Gerbil and hamster balls are not always well insulated, and on hot days the plastic ball can get hot very quickly. Avoid putting gerbils in exercise balls in hot weather, and never let them be exposed to direct sunlight during ball time.
Let the gerbils explore and crawl in by themselves. They will only do this if they want to play, and not all gerbils enjoy exercise balls, so give them the choice.
When putting the animal into the ball, make sure that the lid is screwed in properly otherwise it could fall off during rolling. If this happens then your gerbil could fall out and injure itself.
A big open space on the ground floor of your home is a good place (upper levels have the hazard of stairs). Make sure that the ball can’t become wedged under cupboards or chairs.
Carpet is the best material for allowing exercise ball play. Linoleum, wood and stone don’t have enough friction, and your pet can easily lose control of the vehicle and crash into a wall or other object!
It’s crucial that you don’t try to manipulate or roll the ball when the pet is inside. This will merely result in the poor gerbil being flung around which could hurt him, or at the very least provoke fear and stress. Let your little friend run around using his own legs.
There’s no way out for your gerbil once inside the ball, and the animal has no way of letting you know when it’s had enough. Twenty minutes a day is a good ballpark figure, but if at any point it looks unhappy or ha simply stopped for a long period, take it out and return it to the cage.
Once a day is plenty. Any more ball time than that and your gerbil might get stressed or over-tired.
It’s difficult to tell whether or not a gerbil likes exercise balls, so on the first occasion you use it, keep a close eye out for signs of stress. A panicky gerbil is NOT having fun!