Natthapark Kamkart owns the Intern Lamphun crocodile farm in Ban San Ka Yom village in Lamphun province, Thailand. During recent heavy rains, flooding caused sections of the farm’s wall to break and the owner was faced with a dilemma.

About 100 adult crocodiles could break loose if the wall collapses, endangering people’s lives. His option was to cull all the reptiles he was breeding for the past 17 years to prevent them harming his neighbors, but he would lose his investment in the process.

After consulting his family, Kamkart decided to prevent an escape by killing all his crocs.

Unlike crocs, eels may be harder to hold captive or prevent from escaping a cage. The Japanese eel species in particular are notorious escape artists as revealed in an article published in the journal Current Biology on 9 September.

The article tells how researchers recorded by X-ray video the daring escape of juvenile Japanese eels from predators that had eaten them.

“We have discovered a unique defensive tactic of juvenile Japanese eels using an X-ray video system. They escape from the predator’s stomach by moving back up the digestive tract towards the gills after being eaten by the predatory fish,” said Yuuki Kawabata of Nagasaki University in Japan, Science Daily reports.

How the eels did it was seen through the X-ray video. The slippery fish first inserted the tips of their tails through the esophagus and gills before pulling their heads up from the stomach. They then slip out through the fish’s gills.

“At the beginning of the experiment, we speculated that eels would escape directly from the predator’s mouth to the gill. However, contrary to our expectations, witnessing the eels’ desperate escape from the predator’s stomach to the gills was truly astonishing for us,” Kawabata said, according to Science Daily.