Just Some Ranting and Memes

I have a question

So, ya'll know that Muzan Jackson can turn others into demons through his blood right? But when he first found out he was a demon, how did he even find this out? Like, did he just start bleeding from an attack or smth and then someone comes along injured and gets exposed to it or someone accidentally drinks it somehow...? I feel like he'll probably go 'stay back you vermin,' and they just, idk, fall and come in contact with his blood- now this is just plain illogical at this is point in time😂 Idk, just something I randomly thought about and am still curious on:P
If you have a logical or canon answer, plz tell me.