If your rabbits have a lot of fleas, you can tell pretty easily by setting them in front of you and back-combing through their fur. You'll either find live fleas or "flea dirt" which is flea poop. Flea dirt looks like little grains of dirt but if you put it on a paper towel and we it you'll get a rusty red color since it's composed of digested blood.
Remember to consider other potential external parasites of humans (e.g. bedbugs) as causes for your own bites. If your rabbits are affected it's important to treat all pets in the home and the home itself. There are no good products specifically labeled for fleas in rabbits but good options include selamectin (revolution) or imidacloprid (advantage). Never use fipronil (frontline, parastar, etc) on a rabbit.