Big Dung Beetles & Cockroaches – Yarra Glen

The choice is braver and better than it first appears. Playground animals are overwhelmingly charismatic – koalas, dolphins, frogs, dragons. Dung beetles and cockroaches are the two insects most reliably regarded with disgust, and enlarging them for children to climb on is a deliberate provocation that also happens to be sound biology.

Dung beetles in particular deserve the monument. Australia's native beetles evolved with marsupial droppings and could not process cattle dung, so introduced pasture accumulated it – with enormous consequences for fly populations and pasture productivity. The CSIRO ran a dung beetle programme from the 1960s importing African and European species, and it is one of the more successful biological interventions in Australian agricultural history. A giant dung beetle in a Yarra Valley farming district is commemorating something real.

Cockroaches have a similar case. Australia has hundreds of native species, almost all of them harmless bush-dwelling detritivores with no interest in kitchens, and the reputation comes from a handful of introduced pests.

The Yarra Valley around Yarra Glen is wine and grazing country an hour from Melbourne, and the playground is a well-used local facility rather than a tourist stop.

The hand behind it and its scale are absent from every source located.