When I saw that picture of the snail shells, giant African land snail came to mind, but I was sure they wouldn't be, because Florida! I wonder how they got there. Usually snail shells that size come from the sea, around here. Moon snails leave drill holes in the other mollusc shells and we found a shell as big as our hand, one day! Usually they're the same size as your shells, though.

The last time we visited mangroves we were swarmed by mosquitoes. Hopefully this want the car for you. Hopefully winter is a better time of year in that regard.