What is a black spider with a white spot on the back?

A black spider with a white spot on its back is most likely Phidippus audax, a member of the Salticidae family. The arachnid is commonly known as the daring jumping spider and the bold jumping spider.

Found throughout much of the United States and southeastern Canada, the spiders are typically 1/4- to 1/2-inch in length. They may have several white spots across their fuzzy, black abdomen and legs. The species does not build webs to catch food. Instead, it uses its outstanding leaping ability -- anywhere from 10 to 50 times its body length -- and great vision to sneak up on prey.