Why are the houses on stilts?
There is some history there.
The houses are called chattel houses.
I believe that this building style started right after slavery was abolished. The former slaves wanted the ability to move from plantation to plantaion or from area to area as they went in search of work.
But why do they still have them around now? Well, it's quite common in the Islands for "house spots" to be leased or rented. A house spot is literally that: a spot of land big enough to hold a house. Once the lease period is expired the lessee must leave the spot exactly as he got it.
So the houses are built on stilts so that the house can be jacked up and removed from the property quite easily and moved to another location.
Visitors to some islands (like Jamaica) might see a chattel house being moved...in some cases even by donkey and cart!
I stumbled upon such a picture in the Caribbean Travel and Life photo contest. The picture may be found at the link below and is about picture number 14 in the "winners" section.