No, just bight them. Unless the fleas have a disease, but I'm not sure!

Take it to a vet or get a flea collar

Generally courtesy of your pet-the host animal.

Hamsters do get fleas but it would be most likely for a hamster to not get lice when you buy it from the pet store. It could be possible but it mostly depends on the pet store. Does the pet store seem clean, is the cage seem clean? If not then a hamster might have lice/fleas.

To help get rid of/keep away fleas, feed your animal garlic. This is a natural way to keep away fleas and it doesn't make your pet sick.