Alex immediately felt the change in the atmosphere. A shiver went down his spine, and he was amazed, again, by how animal instincts worked. He could not help but grin, even though he now realized he was being hunted. "What is this thing?" he thought, now reverting to his native tongue of Swedish, as the adrenaline filled him, "This is unlike anything, it's so surreal." His mind was literally throbbing with the fight-or-flee instinct, but he was no animal. He was in control. He remembered some very gory encounters, and reminded himself that he had managed to get out of some pretty nasty situations. This would be no different.
He knew that whatever was out there didn't know his exact position, because it'd already be upon him if it did. But why had it been this close to his camp? Animals would normally stay away from his territory, so there was no prey here, apart from Alex himself. And if whatever was out there was an animal, it'd know by now that there lived another predator here. This wasn't natural behaviour. Maybe, he thought, there's some degree of intelligence? If so, then the fact that it hadn't jumped him yet didn't actually mean that it didn't know where he was. It could be looking at him right now, he thought, as he swallowed.
Alex spent another few seconds before deciding that it was either a predator which hunted predators, in which case it'd find him eventually no matter what he did, or it was an intelligent creature. And if it was intelligent, it could reason... he hoped. So he stood up from his hiding place on what he hoped to be the safe side of his camp, grabbed his trusty knife and walked slowly into the camp, grinning all the while (and thus displaying both his weapons of choice: his knife and his teeth) and listened very carefully for any sudden movements.