When I first moved to Costa Rica I was warned about the Army Ants. The warning was something like they will invade your house and there is nothing you can do but leave for several hours. These ants like to eat everything in their path, so they come into your house and eat all the bugs and than leave. Well, last week I finally had my run in with the army ants. Fortunately, they did not invade the inside of my house just the outside. They stuck around for roughly 4hours. (Word to the wise if army ants invade your space leave for the whole day!)
These guys have a nasty bite so do not mess with them or walk barefoot in their path, you will regret it.