"A plague of locusts?" -- sure. But a plague of kangaroos?
Yanks like me who have only seen a kangaroo in a zoo or a movie may marvel, but it's no damned joke in Queensland, Australia, where road kill is common enough to excite police warnings and fertile fields are scraped dry.
"Sooner or later, they will take our place - there will be no grazing left if we don't do something about it."