Me and a couple of friends were playing with my hamster and the question was asked to me - why do hamsters have tails.
I dont know? and cant seem to find the answer. Is there a reason for the tail??

For most rodents the tail helps with balance and stability.

As an aide you might want to focus a little more on correct use of grammar and punctuation. What ever you decide career-wise an ability to write correct grammatical English will be an advantage.