This little (4mm) wasp built the cells she needs to rear her young utilizing an abandoned length of fishing line. In this photo, she has clamped on to the line with her mandibles and is resting -- something many wasps do.
Pretty sure this thorn hopper is in the genus Umbonia. These lovelies are quite common.
This photo shows an 8-9mm Costa Rican trap jaw ant with her jaws in the open position. Her genus is Odontomachus. If you stretch or enlarge the photo you can see the tiny setae arrayed along the inside of the jaw. If these hairs come into contact with prey her jaws will slam shut. I frequently see these ants (as well as another species of trap jaw) in the forest. They move slowly by ant standards and are relatively easy to photograph.