Do worms have a heart?

Heartbeats: Worms don't have just one heart. They have FIVE! But their hearts and circulatory system aren't as complicated as ours -- maybe because their blood doesn't have to go to so many body parts. Moving around: Worms have two kinds of muscles beneath their skin. read more

Earthworms can have five, 10 or zero hearts, depending on how you define "heart." They have five pairs of aortic arches that run along the length of its body (or 10 single arches, if you count each pair as two separate structures). read more

I have five hearts! All of these hearts pump blood through my blood vessels just like your one heart. read more