The summer green lushness of the Everglades is turning golden as the grasses dry up and the water retreats. We haven't had any measurable rain here for almost a month, and the rich summer growth is turning golden as the grasses dry. Alligator holes are becoming more important as fish, frogs, and other Everglades creatures retreat into the holes that alligators enhance to find moisture. There's a nice picture of an alligator hole here and you can learn more about alligators in general here.
There's some discussion about whether or not the alligators actually build the holes or just take advantage of a natural depression and work on it over time to suit their many needs, but most researchers say that the alligators actually dig the hole with snout and tail, pushing mud out from around the underlying limestone layer. The holes provide water for mating, and bring an unending food source right to the alligator's door as the water supply diminishes. An older hole may be characterized by a ring of trees around the banks, because the additional moisture content allows tree seedlings to survive the dry season, although many holes are just a depression in the marsh.
If you're going for an outing to see for yourself, the Suncoast Herpatology Society has a list of safety tips to check out before you go. One of the nicest small Everglades walks right near Marco/Naples is the Big Cypress Walkway right of Rt. 41 in the Fakahatchee. There's almost always a nice big alligator in the pond at the end.