How to identify gruesome river creature Brits warned that they should kill 'on sight' by stabbing in brain

There's a river creature that authorities have encouraged you to kill on sight if you spot it, but it's important that you know how to identify it first.

You're supposed to kill it by destroying its brain, and its small size means that it's not an impossible task either - and it's important that you do it too in order to protect the environment.

Brits have already been warned about the danger it imposes to our wildlife.

The small river creature is known as the American signal crayfish, which was brought over to the UK in fish farms in the 70s, where many escaped and became a pain in our backsides for decades to come.

You must kill these creatures on sight (YouTube/Angling Trust)

These pesky little things carry a crayfish plague that could prove to be deadly, infecting and killing local river species, as the American crayfish also preys on local varieties that are smaller in size.

As well as this, they have the audacity to beat them to food and destroy their habitats. Selfish p****s.

If this wasn't enough, they can also burrow into riverbanks, weakening the river and increasing the likelihood of flooding.

This is why you must kill them on sight, in fact, it is apparently illegal to leave them alive if you spot one.

Sadly for our friendly European white-claw crayfish, 90 percent of the species has gone, according to scientists' predictions.

There's no sign of them slowing down, as American signal crayfish can grow up to 12 inches long, significantly longer than local species, with females able to carry up to 250 eggs.

So how do we stop the species from going extinct, and identify the pesky American crayfish perpetrators?

Doctor Emily Smith of The Angling Trust, the national governing body and representative organisation for all freshwater and sea anglers in England, has explained exactly what to look for in a YouTube video.

You'll want to make sure that it's not a crayfish of the white-claw variety before crushing its brain, and here's what distinguishes it from them.

The claws

Dr Smith explained that the underside of American signal crayfish's claws is red in colour, and the hinges have a white-like colour that is more obvious on those larger in size.

"If you're identifying those features you can start to narrow in and feel more confident about what you're looking at," she highlighted.

Two small bumps on its head

This might take some inspecting, but you should look for two small bumps on the back of its head.

Explaining the 'the second one might be a lot smaller', the bumps won't be present on local white-clawed crayfish.

There are three definitive features to look out for in the American signal crayfish (YouTube/Angling Trust)

Texture

Near the back of its head, towards the body, you'll want to look at its texture.

Dr Smith explained: "Look at the the kind of texture of the species - so for a signal crayfish it'll be completely smooth, for a white claw crayfish it will have more ridges and some kind of uneven texture."

She highlighted that these features highlight whether it's an American signal crayfish or not, so it's important to look for these if you come across one.

It's important that if you come into contact with one, you should wash your shoes, clean your boats and fishing tackle before heading home.