Colony of black and yellow catterpillars with long hairs. Distinguishable because of their social behavior, and their nest in an alder tree. The nest resembles a white club with many black spots (feces), that is wrapped around a branch of the tree. In this case, the tree was an alder, which means the area needed to be open with almost full sun. The caterpillars construct many rooms inside the tent, which are carefully alligned to have varying relative temperatures. Some peoplle consider it a pest because they will eat the leaves of the tree.
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