I found the same thing today. I don't think they are fleas. They were growing away from a blood source (me) and squished very easily. Hopped like fleas though!
What Are These Extremely Small Black Bugs Hopping In My Bathroom Sinks And Toilets?
More than likely they are fleas. You'll probably need a bug-bomb to get rid of them all. Also have any pets professionally dipped for the bothersome little critters.