Alien Encounters is a website for information on and reporting sightings of non-native amphibians and reptiles in the United Kingdom.  It is part of the National Amphibian and Reptile Recording Scheme.

Alien, or non-native, amphibians and reptiles range from unwanted pet terrapins, surviving as non-breeding animals, to long-established, breeding populations of midwife toads and wall lizards, to serious pests such as the North American bullfrog.

Recording the presence of these animals is sometimes neglected by ecologists, so Alien Encounters aims to collate sightings to find out where non-native amphibians and reptiles occur in the UK.  This will help understand the extent to which these species have become established here.

You can help by reporting your sightings of alien amphibians and reptiles and, in particular, four that are associated with water bodies and are relatively easy to identify.