It may be the male hamsters testies or if it is female it may be a tumor.
a hamster-ball is a ball and in it there is hamster. see my house there will be a hamster-ball. issisabelle is my username
If it fits in your butt
unless the tail is wet, that could be fine. its just the way his/her butt is
you could. but a hamster ball is dangerous for a hamster so it most likely be dangerous for a gerbil as well.
The pet store, of course!
Place it in. If it bite were gloves
pink
A hamster wheel is used in the cage and is powered by the hamster its self. A hamster ball is what you put the hamster in to exercise when you are cleaning the cage. A hamster ball is heavier so would probably go a bit slower but both are actually powered by the hamster its self so it depends on how fast it goes.
The hamster gets more exercise because he is pushing a ball. Plus it is easier to catch than the hamster itself.
a wheel in its cage or a hamster ball
Seven inches
it depends on the hamster