Since hamsters are rodents, their teeth never stop growing! 

There are wild hamsters in Europe and Asia. 

Unlike dogs, there are not different breeds of hamsters - the different types are different species, which means they can not interbreed. Only one combination can breed and breeding them will cause health problems. 

Hamsters are almost completely blind. They can only see a few inches in front of their nose and rely on their other senses, like smelling anhearing. They have very sensitive hearing because of this so you should never be too loud around your hamster. 

Hamsters have two types of poop and can tell the difference between them. One type still has nutrients and hamsters eat the poop to process the rest of the nutrients. This is completely normal and safe, don't worry!