Eaten water beetles stay alive by escaping through the predator's anus

Pictured above is (a) an adult aquatic beetle Regimbartia attenuata, (b) the potential predator Pelophylax nigromaculatus and (c) R. attenuata escaping from the vent of P. nigromaculatus.

(CNN)Because of their small size, water beetles might have been kicked around since they were born — but thanks to abnormal survival strategies, they're "stayin' alive" after predators eat them.

Meet the aquatic beetle Regimbartia attenuata, which can survive a journey through a dark-spotted frog's gut and exit alive through its feces, according to a study published Monday in the journal Current Biology.
The pressure of being hunted is typically what leads to the evolution of different escape behaviors in prey animals. Surviving the extreme conditions of an animal's digestive system is a wild card that depends on the prey animal's ability to move quickly through to the, ahem, escape hatch.
    Such a deadly environment could impose speedy and active escape behaviors on swallowed prey species — so Shinji Sugiura, the author of the study, tested this hypothesis with aquatic beetles and dark-spotted frogs.
    After the frogs swallowed the beetles, 90% of the insects were excreted within six hours of being eaten "and, surprisingly, were still alive," said Sugiura, an associate professor in the department of agrobioscience at Kobe University in Japan, in the study.