Why did the monsters chase Daniel?

[Tanshaydar]

The Servants are unknown to be human formerly.
They were to catch humans for Alexander's experiments. See the "The Gatherers" memo. And Alexander's note "Regarding Closing of Wine Cellar".

Daniel has one memo about them too, about their scent.

Just try to read every note, flashback and so in the game. I can bring up from the language file, if that helps.