Scribbly

Scribbly Gums are all over the place. The name is claimed by several Eucalyptus species (including haemastoma and sclerophylla in the Sydney region), but the artist is in fact a moth.

The scribbles are made by the larvae of the Scribbly Gum Moth (Ogmopraptis scribula - thanks again, Wikipedia) which troll around between two layers of bark, having their creations unveiled when the outer layer peels off. There are usually loops at either end of the tracks, implying that the larvae get tired of exploring, and turn around to follow their trails back again.