Underground cave explorer stops in his tracks and leaves after spotting something on the walls

Not everyone is cut out to be a cave diver, and as it turns out, even seasoned adventurers can come up against their match every once in a while.

ActionAdventureTwins are identical twin explorers called James and Edward, who have been sharing their viral videos of themselves exploring caves in America.

But when one half of the pair decided to take a look into a location suggested by a viewer, and ended up cutting things short.

While the location wasn't given on the video, considering they don't leave the US for their videos, it at least means it's somewhere in the region.

According to the video's description, 'it's not worth it', which really raises the question of what exactly did the twin encounter?

Viewers think they spotted someone's belongings left in the cave (YouTube/ActionAdventureTwins)

At first, one half of the due claimed there were animal faeces on the floor and said he immediately regretted not 'bringing his gun'.

"I am so ill prepared, I got no knee pads or gloves, short sleeve shirt, what am I doing?" he said.

However, later in the video, the brother was stopped in his tracks after spotting some 'blood' on the rocks.

The YouTuber got out of there as quick as possible after spotting blood (YouTube/ActionAdventureTwins)

"I think that's blood," he said, "oh my god guys, I think there's actually blood up there."

That's when the cave explorer decided enough was enough and got himself out of there.

Viewers were stunned by his lack of preparation on such a dangerous solo-mission, as one person commented: "'Is that blood?' has to be pretty high on the list of questions you don't want to be asking yourself in the middle of a cave."

Another added: "No caving gear, no safety gear and all alone deep in a cave... This is a recipe for a disaster in the making with this guy..."

"This is a loose cave; highly dangerous for all professionals. You already know this information; try not to listen to the evil voices that told you to explore alone," warned a third.

"Every time you mentioned seeing more bear tracks, I can’t believe you kept going in further. Omg not safe, especially all alone.

"The blood freaked me out and then you mentioned that whatever was out hunting would be heading back in. Holy cow."

Meanwhile, others thought they noticed someone's belongings in the video.

They wrote: "That stuff on the ground at 15:42 looks very much like a smartphone on the left (partially obscured by rocks, screen dirty if facing up; might be upside-down) and on the right (the blue thing) what might be some sort of bag (perhaps for the phone; if it's a bag, it seems damaged), and left of the smartphone-looking object there's what looks like two AA or AAA batteries (next to a rock that's about the same length as the phone."

Well, it seems that fans of the explorer are hoping he takes better precautions next time.