For sure fleas not anything to mess around with, don't try to save money with bombs and sprays, check with a Vet to get recommended applications. Does no good to bathe the cat or dog's fleas away or put on a flea collar when your carpet or your bed is full of them, and yes, they do love people's blood as well. Put out a shallow of water on the floor (a couple drops of dish soap in it so they can't get out) with a light shining on it, and see what you have in the morning. Will tell you exactly how bad the infestation is, whether it's fleas, bed bugs, or other. This is scarey stuff, especially if you have little kids. Yes they do transmit disease to humans as well.
Make sure to read the labels of your chemical bottles, this is something that must be repeated in a timely way to kill every succeeding generation.
Fleas are the scourge of the earth, and the epitome of survival through Millennium!