There are many ingenious creatures that have devised ways to trick plants into growing structures, called galls, which shelter and feed them.
Directions: Meet at the gate on San Andreas Dr. in Novato. From Hwy 101 in Novato, take the exit for San Marin Dr. west 2.3 miles. Turn right onto San Andreas Dr. and follow approximately 0.5 miles. The gate is on the right (before dead end).