How can you tell the difference between a crocodile and an alligator?

My friend Jameson posed this question yesterday. My answer, was terrible-

but likely not nearly as bad as some of the others.

my answer was terrible:

one always arrives on time and fully cocked-n-at-the-ready, the other one smokes a fuck-ton of pot and falls asleep mid river or near the banks often, and relies on a most unusual hunting strategy. he falls asleep until his prey bump into him from either an accident or the current of the moving water, and then he snaps the shit out of them and gobbles them up like the little surreptitious happen-chance river Doritos they are.