The snake was sleeping in the fireplace when it struck out
Removal men clearing an empty house were attacked by an escaped exotic snake sleeping in the fireplace.
The reptile - a yellow rat snake - struck at one of the men but did not bite him.
The 4ft-long constrictor, normally found in South Carolina, is not venomous but will bite if not handled carefully.
The council workmen - who saw an upturned glass case when they went into the house near Ammanford, south west Wales, but did not suspect a snake would be near by - were able to put the snake back behind glass.
The creature, also known as a corn snake, is being cared for by Llanelli-based snake expert Geraint Hopkins.
It's not really the kind of thing you want to happen anywhere
He said the snake had probably not eaten since the home's last residents moved out a month earlier but had been helped by the warm weather of the past weeks.
"It was curled up the fireplace. It had obviously been in the house a month.
"The workmen were cleaning the house out. They went to clean the fireplace and it struck at them.
"Most rat snakes are aggressive but their bite won't actually kill you.
"It was pretty shocking for the council workers - they had quite a fright - after that it was more of a joke.
"It's not really the kind of thing you want to happen anywhere."
Mr Hopkins holds the aggressive yellow rat snake
Mr Hopkins said the workmen had used a litter-picker to put the snake back in its case by the time he arrived to adopt it.
He said the latest addition to his collection was "a bit thin and hungry" but otherwise unharmed by its temporary freedom.
But he warned against people wanting to keep snakes as a pet.
"The problem is there are so many people buying snakes in pet shops and, because they know nothing about to keep it, they lose it quite quickly."
"If the workmen had not cleaned the house out, and new owners had gone in there, can you imagine what would have happened?"
"Although its a constrictor, it has a very nasty bite and could do a lot of damage."
In January this year, a north Wales garage owner had a major shock when he found a five-foot albino Californian kingsnake lying in the footwell of a car he was repairing.
Dave Matthias, from Summerhill near Wrexham, discovered the snake, Milkey, seven months after he went missing from his owner's car.