Police are hunting thieves who have taken 22 young python snakes from a reptile breeder's garden shed.
The pythons were kept in artificially warm conditions
The snakes, described as "gentle" and no threat to people, were grabbed from a house in Birchgrove, Swansea.
The royal or ball pythons, measuring 18in to 2ft (45-60cm) in length, were kept in 14 boxes with lockable lids.
The owner has said the African snakes could die within a week if they were not kept in an environment with a temperature above 90F (32C).
The creatures and the boxes containing them were taken in the break-in, reported at around 1820 GMT on Wednesday evening.
The reptile breeder was breeding the snakes to be domestic pets. The snakes were described as "only half grown".
In a statement, South Wales Police said: "These snakes were bred specially as domestic pets and are harmless to human beings.
"Once fully developed, they can reach an average length of 3ft-3.5ft [91-106cm]."
The containers were described as translucent toy boxes.