Processionary Caterpillars (Ochrogaster lunifer), also known as ‘itchy grubs’ are the larvae of the Bag Shelter Moth. They are found in all mainland states and territories in Australia, and feed on the leaves of a variety of shrubs and trees, particularly acacias, eucalypts and some Grevilleas. The caterpillars feed at night and return to their communal bag-like nest during the day, and then form processionary lines in Spring to locate places to form a pupa before developing into an adult moth. The caterpillars and adults are covered with millions of microscopically barbed irritating hairs that can cause serious rashes, eye damage and allergic reactions in sensitive people. These creatures and their nests should not be touched under any circumstances without wearing protective clothing, and medical attention should be sought if affected by the hairs.