Western pebble-mouse

Pseudomys chapmani Male: 52-67mm Female: same

SOME OF THE strangest constructions made by animals in Australia are the mounds of stones, up to 9sq.m in area, built by the western pebble-mouse. These small rodents move thousands of pebbles, each weighing up to half their own weight, to create a landscape dotted with miniature stone ‘volcanoes’ in which the ‘craters’ serve as burrow entrances.

As many as 25 mice live under one mound. The purpose of the pebbles isn’t yet known, but probably has to do with maintaining humidity underground and stopping goannas from clawing their way in for mouse meals. The mounds last decades, if not centuries, providing homes for numerous generations.

The western pebble-mouse lacked a scientific name until 1980; since then, two more pebble-mouse species have been named.

Scientists began naming Australia’s rodents during the 18th century, so it’s surprising that these mice eluded recognition for so long, given their durable engineering works.