All About Fleas
There may be fleas in your home. Ugh. So let us go over all sorts of flea knowledge so you know all about fleas.
Fleas bite animals because they need the protein in the blood of the victim in order to produce eggs. So, male fleas do not bite. Just the females.

Fleas can reproduce better than most species. Just one female can produce 2000 eggs within a 100 day lifespan. They reproduce and then the offspring reproduce, and it can grown exponentially in a short time.
Contrary to what many believe, fleas do not like to live on animals. They hitch a ride on certain animals to get a blood meal and lay eggs, then drop off in more preferable areas, typically where the animals sleep. Nap spots are a perfect environment as the unknowing prey animals are fast asleep when fleas come and go biting away.

Fleas lay eggs in the fur of their prey so that eggs will hatch and have the opportunity to drop off where the host animal sleeps. Host pets come inside and flea eggs drop off in the home and are often swept away to the floor baseboards awaiting their future. (Very important because cleaning a house with a flea infestation means extensively cleaning baseboards!)

Fleas do not prefer humans. They prefer roaming, outdoor sleeping animals. But if they need a blood meal to lay eggs, a human will do just fine!
Getting rid of fleas is two prong - controlling adult fleas and controlling flea eggs. Greenbug controls fleas and here is the link.