The amphibians can remain in their tadpole form due to overcrowding or poor weather conditions.

Tadpoles have decided not to turn into frogs because of this year’s bad weather.

The young amphibians usually begin their transition into frogs in the UK during April and May, but they have been seen still swimming in Cumbria.

Jodie Mills, from the West Cumbria Rivers Trust, said tadpoles had been spotted in a river in the Walkmill Community Woodland, near Moresby Parks.

She said the animals decided early in the year whether they would stay as tadpoles or “metamorphosise into tiny baby frogs”, depending on whether conditions were right.