How long do flea bites last?

Depends. If you have a type 1 allergy to insect saliva, should be gone in 1-2 days. If type 4, could last for weeks.
It depends. If you are not getting rid of the source of the fleas, you will keep getting them. Use an appropriate pesticide (safe around animals) and have your pets treated as well. Avoid scratching and keep all bites clean. Caladryl clear may help prevent itching, and allow them to heal more quickly.

Related Questions

How long do flea bite scars last?

Scratching. Depends on how much you scratched them. If you were able to leave them alone they will fade in a few days, if there is a large abraded area, anywhere from a few weeks to a permanent scar if a large area was opened. Read more...