Passengers were awaiting take-off of the 10.40 BA service to San Francisco yesterday (March 1) when crew alerted them to the discovery of the rodent.
Staff announced that the flight would be unable to depart the London terminal and a replacement service was scheduled, which left around four hours later, BBC News reports.
One passenger, Carly, said there was "general disbelief" among her fellow travellers after the news of the furry stowaway was broken.
"I’m not sure people knew how to react," she said.
Other passengers voiced their reactions on social media.
Matt Watt tweeted: "Just had my flight to SFO cancelled because of a mouse on board the plane. Could it not get a visa?? #britishairways",
https://twitter.com/markwatt/status/836894174372892687
Another passengers @midlandsound created a Haiku to describe the bizarre incident: "About to fly to SF, There is a mouse on the plane, We all must get off."
https://twitter.com/midlandsound/status/836892984641785857
He later wrote: "I’m going to sell this to the movies. It can be the slightly more pedestrian prequel to snakes on a plane. Maybe this is what lured them on?"
A spokesperson for BA was quoting by BBC News as saying: "We know almost everyone wants to fly with us to San Francisco, but on this occasion there was one very small customer who we had to send back to the gate.
"Everyone with two legs is now on their way to California, and we are sorry for the delay."
Heathrow officials said they were unable to comment on individual flights.
