TORONTO, Jan 8 (Reuters Life!) - A stowaway scorpion that stung a man on board a plane headed to Toronto caused a delay at the airport as investigators combed the aircraft for further arachnids, an airline spokesman said on Monday.

The scorpion apparently crawled out of the man's carry-on knapsack on American Airlines flight 1552 from Miami to Toronto on Sunday morning, said John Hotard, a company spokesman in Fort Worth, Texas.

"We delayed the outbound flight and searched the cabin of the aircraft to see if we could find any more, which we did not," said Hotard.

He said there was no indication the scorpion was brought on the plane intentionally.

A return flight to Miami was delayed by less than an hour after touching down at the Toronto Pearson International Airport.

Hotard said the man told airline officials he was returning to Canada from a camping trip with his brother in Costa Rica, from where the scorpion likely originated.

"This is rare," said Hotard. "I'm not aware of a scorpion stinging a person on any of our flights before."

Still, "we get critters on board from time to time," he said.

After the plane touched down in Toronto, the passenger initially said he was alright but then reported feeling some "numbness," said Hotard, who couldn't provide further details on the man's health.

Fire and emergency crew responded and the man was treated by paramedics before being taken to hospital, the Greater Toronto Airports Authority said.