(CNN) -- Could you catch a wild gorilla? What about a person dressed as a gorilla?
This week, staff at Tokyo's Ueno Zoo practiced capturing escaped animals by chasing around one of their colleagues wearing a gorilla suit.
Visitors gaped as scores of helmet-wearing keepers surrounded the "gorilla" with cars and nets. Staff then pretended to tranquilize their coworker, who swooned dramatically and collapsed to the ground.
The acting ape was immediately wrapped in a large net and hauled away on a truck.
The escaped animal drill at the Tokyo zoo is conducted every other year, and this time zookeeper Natsumi Uno was chosen to wear the animal costume.
"In our work there may be times when we need to capture an animal, but we would never be the ones being captured," Uno told reporters.
"So I tried to feel what an animal might feel and realized when they were on the run they would be scared. That's how I felt."
But some onlookers were barely moved. One Japanese user posted on Twitter, "Ueno Zoo's escape drill wasn't tense at all."
Another wrote, "The gorilla escape drill was so laid back! Made me laugh."
The practice is part of the city's earthquake preparedness drills, where city workers prepare for scenarios that may occur in the event of an earthquake.
That includes capturing raging beasts.
In the past, the Ueno Zoo has tried using different animal outfits: In 2004, two men ran around the zoo while wearing a giant papier-mâché rhinoceros over their heads.
The technique isn't just Japanese -- in 2012, the Franklin Park Zoo in Boston, Massachusetts practiced capturing an employee in a giraffe costume. The year before that, zookeepers in China "caught" a man dressed as Tigger from the "Winnie the Pooh" cartoon.
Of course, real animals are more difficult to catch.
When an actual monkey escaped from the Ueno Zoo in 2010, it took six hours before officials finally netted it in the basement of a neighboring restaurant.