Although I knew there were American Signal Crayfish (Pacifastacus leniusculus) in our pond, we don't often see them. It was a case of out of sight - out of mind, until I found this one, today, in the stream that feeds our pond.
These crayfish are a non-native species and their release into the wild in Britain is a disaster for our native wildlife. They are voracious predators which have almost wiped out our native crayfish. They eat fish, plants and invertebrates and cause erosion problems along riverbanks.
This one was about 6 inches (15 cms) long.
I am not really sure what we should do about them. Should I start trapping them?