Stonefish toxin tested against parasitic worms / This is what it looks like when parasitic worms directly invade your brain / Doctors find worms squirming through teen's neck: A cautionary tale / Screwworm: Why is this flesh-eating parasite making a comeback? / RFK Jr. isn't the only one. More than a billion people have parasitic worms / Rare bear meat at gathering gives 10 people a scare--and parasitic worms / Can we live on worms alone? Probably not, find scientists / A new pill cures preschoolers of a parasitic worm. Delivering it could be a challenge / RFK Jr. is not alone. More than a billion people have parasitic worms / RFK Jr. says he had a dead worm in his brain. What are these parasites and how common are they?