Beware of borrachudos!!!
There are lots of bugs in Brazil. But the ones that are most anoying are on this island. They're called borrachudos. Although I never saw one, I felt their bites on my skin. They bite during dawn or dusk (not during the night, as we thought), so put on a lot of mosquito repellent all day. It's a must. Or you'll become mosquito lunch.
The ship warned of humongous mosquitoes and handed us little bags of repellent. But none were encountered.