If you think your hamster has fleas, there are a couple things you can do to check if it does.
1) First comb the hamsters fur to see if there are little black specks moving around, or if there are little white dots at the base of the fur.
2) Look at your hamsters bedding. If the hamster has fleas there will be black dots moving around in the bedding.
Although hamsters can get fleas, it is unlikely for them to get fleas. This is because they would need to come into contact with some animal, or something that has fleas on it.
If your hamster has fleas, you will need to get flea spray that is safe for the hamster. Make sure the spray you get is safe for small animals. Flea spray for dogs and cats is not safe for smaller animals.
You can go to your pet store or vet to get more information, or to buy the right flea spray.