Passengers could be heard shrieking in panic as a rat ran around a packed metro carriage.
Footage from inside the women-only carriage shows some passengers scrambling towards the exit.
Others could be seen hopping to stay off the floor, or standing on seats, as the rodent scuttled through the carriage.
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The scare unfolded on a Line 2 train heading towards Pavuna on the Rio de Janeiro Metro, Brazil, on Friday (8 May).
The train was between Cidade Nova and Maracanã stations when the rat was first spotted, as reported by Need To Know.
The clip was filmed by cleaner Katia Aparecida and has racked up more than 1m views online.
One woman could be heard wailing: “The poor don’t get a day of peace.”
During the commotion, Katia was injured when another passenger fell onto her.
The woman could be heard apologising: “Miss, forgive me. I jumped on you, I’m sorry.”
One viewer joked: “The rich don’t have fun like this.”
Another person quipped: “The floor is lava.”
A third viewer added: “A few minutes earlier, nobody knew each other.”

A fourth person remarked: “I would’ve already fainted thinking about hantavirus.”
And a fifth person said: “So much FOMO.”

MetrôRio said staff were not called to the incident, but stressed it “regularly carries out rat extermination and other pest control across the metro system”.
The company added: “Cleaning is carried out daily at various times.”
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