its like this, a milk snake is a kingsnake but a kingsnake isnt necesarily a milk snake. kingsnake is the genus, and milk snake is the species. kinda like a taod is a frog but a frog isnt neceasarily a toad. or saying is a timber rattlesnake a rattlesnake? yes, because a timber is a species in the rattlesnake genus crotalus. a milk snake is a species in the kingsnake genus lampropeltis.