The man didn't have a permit for the six venomous snakes - five rattlers and a gaboon viper - and he may face misdemeanor charges for keeping them without a permit. The viper, native to Africa, is considered one of the most dangerous in the world with potent venom.
The snakes were inside cages in a separate room and were removed as firefighters quickly put out the blaze on Friday in Clearfield, about 30 miles north of Salt Lake City.
"I don't think firefighters were ever in danger from the snakes, except for the creep factor," said North Davis Fire Chief Mark Becraft.
The poisonous snakes were confiscated by the Utah Division of Wildlife, where Capt. Tony Wood was trying to determine their fate - and whether to cite the owner.
"I'm just trying to wrap my head around the situation," he said Monday.
Fire and smoke damage left the man's duplex uninhabitable, Becraft said, but all the snakes survived.
The owner took his 22 other legal snakes for safekeeping to his father's house, Davis County Animal Control Director Clint Thacker said.
The seized rattlers will probably be released into the wild, and the viper could be sent to someone authorized to have it, said Jim Dix of Reptile Rescue of Tooele County.
The owner has been described variously by officials as a snake professional or breeder. Dix said the snakes were well fed, in good condition and that there was no threat to anyone in the neighborhood.
"We are seeing a big increase in illegal animals in Utah," he said. "It just goes on and on."
Dix said he was working with Utah officials to designate "amnesty" days for unlicensed owners who are willing to turn over exotic animals.
Earlier this year, Cottonwood Heights police cited a young man for failure to have an exotic pet permit and initially ordered him to get rid of all but one of his 29 boa constrictors he kept in special room in his basement with top-of-the-line cages.
The Cottonwood Heights City Council later gave him a reprieve, allowing Thomas Cobb to keep his snakes while officials revisit the city code.
Cobb still has the snakes he says are worth $12,000 apiece, and is waiting a resolution from city officials, Cottonwood Heights Police Sgt. Mark Askerlund said.