https://www.reference.com/pets-animals/food-chain-american-alligator-2b07526ac7c4da5d
Fish and turtles are the most important prey for most alligators, but they are not fussy eaters.
Other common prey species include snakes, frogs, toads, salamanders, birds, lizards, beavers, raccoons,
nutria, rats, crustaceans, mollusks, insects and smaller alligators. Young alligators feed on smaller prey,
including insects, frogs and fish. Alligators of all ages adapt to local food sources, but they are strictly
carnivorous and do not eat vegetation.
Wading birds, snakes, large fish, turtles, raccoons, foxes and larger alligators hunt young alligators. As
they grow, young alligators add more and larger prey to their list of acceptable food. Concurrently,
alligators fear fewer predators as they grow.
Alligators are an important part of freshwater ecosystems as they help to maintain balance among the
populations of small animals. Additionally, turtles and some other animals deposit their eggs in
alligator nests.
I think the big boys take hogs and deer. Supposedly the gator in question was a 7 footer (not exceptionally large), so it probably rolled the child underwater then figured out it wasn’t prey and left. Sad. Gators are everywhere and can stay underwater for long periods of time, so we don’t really see how many there are. Check swimming pools before jumping in - they’ve been known to hang out in chlorinated water and salty water for brief periods.