Orchid bee, Euglossa sp., from Panama.
A sphecid wasp (Sphex sp.) carries a paralyzed katydid back to her burrow. She has stung and immobilized this katydid not for herself, but for her progeny, as she will bury the still-living host alive with a single egg in a tactic known as mass provisioning. Another really cool behavior I witnessed: these wasps are smart enough to know that they will get to their destination with their heavy load faster and with less effort by climbing up a tree or small plant and gaining some altitude before taking off and fluttering slowly back to the forest floor.
A leaf-cutter ant (Atta sp.) uses her razor-sharp mandibles to cut through a leaf in Panama. A recent study has shown that as leaf-cutter workers age and their mandibles dull, they gradually switch to leaf-carrying tasks to maximize their usefulness to the colony.