Well, if you have a hamster, you should probably count how many days/months/years you had him or her, and they should be older than that. A way to tell if a hamster is young is that he or she will be more hyper.
Old Hamsters are Lazy, also have bad teeth then usual
Hamsters' weigh is depended on its diet,size and its age.
easy just remember when you got him and how old he was then add them together then take away from the date today
They get a lot fatter.
Dwarf hamsters have an average lifespan of 2-3 years.
Yes. If not intergrated with other hamsters (including even averaged sized hamsters) at an early age, they do become defensive and territorial. This can go as well with an average hamster. But remember, this may vary from animal to animal.
look at its privates
Lazy and bigger nipples means ready to give birth
hamsters can only live for three years so they die when they are 3 years old
Baby hamsters leave their mother at three weeks old.
This link should tell you everything you need to know about hamsters! http://hamster-care.com/breeds.html
When they open their eyes.