They are incentive-training the alligators to come up on land when
the stick is tapped on the ground in front of them. Only
the one that the stick is right in front of comes up.
Using the same stick, the alligator is lead to a spot where
it stays in place while a physical inspection is done of them
to ensure all is well.

The alligator is rewarded with small frozen/thawed rodents for it's effort.