Not exactly what you would really call a 'danger', but they can drive you crazy. The problem is these critters are so small, you don't notice you're being attached until you're covered in small bites that itch, and itch, and itch. It was only after our trip that I read that sandflies do not like 'coconut' (which probably explains why you can buy coconut oil everywhere on the island). Unfortunately, in my case, I found out too late - zillions of bites later. So, do yourself a favour, use coconut oil and try not to lay directly on the sand.
Beware of the insect. They will bite you anywhere any place. Especially night time and day time when you stay under the trees.
Have to bring.
1. "Go away insect lotion" What i meant is anti-mosquito lotion. Johnson's baby clear lotion is quit great. or there is lemon grass lotion too. (product of Thailand) but it has strong fragrance.
2. Anti-itching gel / healing,, i was itchy everywhere.
Dont forget. That's the most danger that i can thinking about ;-)