A very Flattened species of cockroach which adheres tightly to log surface, Even Grey / Camouflaged colour. Keeps very still (not moving). Distinctive Large segmentation, long antennae.
hi Max, the long antennae are a feature of all members of cockroach families (adults and larvae); your photos depict a larva given the wings are not developed, being flat and segmented is a feature of all Blattodea . I assume it is a common wood cockroach which lives in rotting wood; visit Panesthia australis for more info and photos of adults and larvae of various stages.
interesting - I wouldn't be able to tell the difference between Laxta and Panesthia larvae from the photos; thought larvae of Laxta members are more brownish and larvae of Panesthia australis more shiny.