It starts with 'him' flying into my room yesterday and don't know how he did it as my room was at 9 storey height.
Well, do you know that you can't kill a cockroach by simply smashing it flat?
Cockroach is not as cute as you think. By flattening it, you will pollute your room with various bacteria knowing that they love living within the rubbish pit. You know, it's like they are actually kamikaze or mobile mine bombs. All you can do is to spray it dead with poison.
That's why, many people are afraid of flying cockroaches as they are like flipping those dirty bacteria towards you!
Indeed, they are disgusting but please be patience while you try to kill it. Or else, your room is gonna be seriously damaged.
Good Luck!