One morning of our trip we spent hiking in Carara National Park. Even though we didn't see all the exotic birds we'd have liked to have seen, it was an incredibly beautiful hike.
One of the first things we saw was the chains of cutter ants that had established "highways" where they'd cross the trails with their leaf cuttings to take to their homes.
agouti. We actually saw a pair first...one of which ran away before I saw it and this one who seemed to think itself invisible.