Thanks to the half-moon shape of their heads, hammerhead worms are known by many names, including hammerhead flatworm, arrowhead flatworm, and broadhead planarian (a category of flathead worms).

You probably already know that North Carolina has lots of snakes. So you might not give a long, skinny thing slithering along the ground a second thought. “Yep,” you’d say to yourself, “just another ...