Terrapins are taking over our waterways

They began their lives as pets, fuelled by the Teenage Mutant Ninja Turtle craze.

Now the number of terrapins in London's canals and rivers has rocketed, according to a major study of aquatic wildlife.

Mary Norden of British Waterways warned: "People shouldn't approach them - they have a nasty bite and are quite destructive, eating birds' eggs and small animals like baby ducks."

Last year ducklings in a Mill Hill pond were dragged underwater and killed by a group of terrapins.

Experts say there are hundreds of dinner-plate sized terrapins in the Regent's Canal and several other waterways, including the Grand Union Canal at Kensal Green and the Lee Navigation at Tottenham.

Ms Norden said warmer weather could trigger a population explosion which would have to be "humanely controlled".