There are a plethora of factors that can cause the gators to appear. They can appear more often after they win the national championship etc.........
Seriously, they can be caused by bad,not agitated gel,cold temp,improper mixing,not waiting for the gel to cure,etc. Also make sure the mat layer is catalyzed "hot" as this will decrease the possibility of the gators appearing.
It also helps if you beat them for the championship, then they won't appear till next year!