( 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 was n'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 is n'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 .
Japanese zoo practiced capturing escaped animals by chasing colleague in gorilla suit . Score: 6 In 2004 , the drill was conducted with two men inside rhinoceros costume .