Take your hamster to a vet, or go to a pet shop. I live in the uk and i know my local pet shop and pets at home sell this stuff called "Beaphar spot on for hamsters, gerbils and mice" and it gets rid of fleas, ticks and mites. Its ￡ 4.30 where I live. If you live in a different country, visit a few pet shops and see if they sell it, if not go to a vets and you can probably buy it for about $ 6 if you live in the usa.
I hope I helped.
Take the poor thing to the vet of course!
