In Campanario, these ants patrol much of the forest. When agitated, they move into a defensive position with their abdomen below them, pointed as a gun. I know some ant do it, so I suspect they are capable of spraying formic acid at offenders.
This spider web holds together the cliff face on which it rests. It reminds me of Hydropsychid caddisfly larva, which weave funnels to capture food particles in streams and have actually been shown to alter sediment transport dynamics.