Steven J. R. Allain introduces an unusual amphibian interloper which was first imported to Britain in the early 20th-century and has thrived in certain towns and gardens ever since.
For the past 120 years, a regular beeping sound has been emanating from certain parts of the British countryside on warm, damp evenings between May and September, following the introduction of an unusual species to Bedford in the early days of the 20th century (Boulenger 1919).