A stray fly briefly commanded the US national stage, generating buzz when it perched on Vice President Mike Pence's cropped white hair as he debated his Democratic rival, US Senator Kamala Harris.

The insect sat there for several minutes during the event, distracting viewers who perhaps may have been looking for a break from all the talk of taxes and trade.

The fly hung on as the Republican former congressman and former Indiana governor shook his head and parried with Ms Harris, appearing secure in the knowledge that the candidate was not in a position to shoo it away.

A short time later, it was gone, but its legend was only growing.

On Twitter, an account named @MikePenceFly swiftly gained thousands of followers.

Ms Harris's running mate, Democratic presidential candidate Joe Biden, posted a picture of himself with a fly swatter on Twitter, asking supporters to "Pitch in $5 to help this campaign fly".

His campaign set up a website, flywillvote.com, to register voters. Within the hour, it was selling a "Truth over Flies" flyswatter for $10.

Mr Pence's staff chose not to capitalise on the uninvited guest.

In a post-debate call, senior adviser Jason Miller had a different animal in mind.

"We had a deer in the headlights look from Senator Harris tonight," he said.

Some Democrats took the opportunity to bring up President Donald Trump's Covid-19 infection.

"The fly needs to be quarantined," Democratic Representative Ilhan Omar wrote.

Republican Senator Rand Paul had a different spin: "The deep state planted a bug on @VP. This illegal spying is really out of control."

Stephen Colbert, host of 'The Late Show' on CBS, suggested that by remaining perched in Mr Pence's hair for two minutes or so, the fly had a greater attention span than President Trump himself.

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