Warnings of stowaway snakes and tree-frogs hiding in plant pots

“Adult snakes and lizards are the tip of the iceberg,” said Prof William Sutherland, from Cambridge University. “If they go through, what are the chances we’ll find small insects and fungi – the things that really cause problems?”

The production of ornamental plants is growing rapidly and is expanding geographically, especially in East Africa and South America.

While regulations and border checks are in place, the volume of cut flowers and ornamentals being traded so quickly makes it very difficult to intercept all the pests and diseases they carry, says Dr Silviu Petrovan from the University of Cambridge.

“Even with good intentions, unwanted hitchhikers bypass customs import checks every time,” he said.