Observation notes: Hundreds of these caterpillars were found in a large arroyo. Walked for approximately 1 mile up the arroyo and saw at least 5 each step taken. Monsoon rains have been taking place this month. Soil was moist. A variety of desert plants were nearby. Many caterpillars were found digging the back side of themselves into the sand leaving the top half of their body exposed. When handled, caterpillar would "spit" an orange/brown liquid. If disturbed in any way, caterpillar would writhe (for at least one minute) and then play dead on their side.
Verified by: kmortensen
Verified date: April 28, 2014
Coordinator notes: Thank you for sharing the behavioral details and wonderful photos.