Kingsnakes and coral snakes look pretty much the same, with bright red, black, and yellow stripes. However, the coral snake is venomous and quite dangerous, while the kingsnake is a good snake to have in your backyard, as they will hunt mice and other snakes. Fortunately, there is a way to tell them apart, as the stripes are in a different order on the snakes. Many children in America grow up knowing some variant of this rhyme:
"Red touch yellow, kill a fellow; red touch black, friend of Jack."
or
"Red on yellow kills a fellow. Red on black, venom lack."
It is worth noting that this rule only holds east of the Mississippi, and also don't pick up snakes based on children's rhymes.