We went on a hike in the Mt. Tamalpais national park with ranger Dave. Hikes with him are fascinating - he finds creatures (salamanders, centipedes, frogs...) where you wouldn't expect to look, and can tell a good story.
Northern California is experiencing a drought, and the lake on which the frogs breed was dry. Some of the frog population was apparently still hanging on, because we could hear them in the trees.
We found tiny holes made in acorns by acorn weevil larvae: