Processionary caterpillars (Ochrogaster lunifer)

Processionary caterpillars are covered in fine, venomous spines which contain a potent anticoagulant. During the day they shelter communally in a bag nest made of silk, leaving in the evening to feed on wattle trees and Grevillea striata (Beefwood). Once they have totally defoliated their tree, the caterpillars migrate to seek out another one, leaving a silk trail. There can be a hundred or more caterpillars in a head-to-tail procession, kept together by contacting the tail hairs of the caterpillar in front. A trick, sometimes played by children, is to join up the head and tail of the procession so that the caterpillars follow each other in a continuous ring. However, these caterpillars are best left alone because contact with their long hairs causes an intensely itchy dermatitis and can result in severe allergic reactions in some people.