Could demons ever successfully invade planet Earth?

Asking for a friend.

LOL, this is probably a Religion forum question. But I will say no or they would have done it by now. 

Yes, because they are supposed to be extremely powerful and can easily overpower us.

No, because they aren’t existent beings as of now, and would have done so if they exist actually concerning of their nature.

I agree with Poly

And how do you know they haven't?

I would think if they could invade we could experience them. I have not. So I would say they haven't. Now that doesn't mean you can't interact with demons, just that a full scale invasion has not. 

Science and nature.

Perhaps there should be a fantasy category.

Or was it a metaphorical question?

Interesting answers. My childhood village had some of the wildest superstitions including demons regularly kidnapping children with a bamboo pole. I was also taught not to say certain words and to slap my ear to ward off demons. That's not to say that I believe in them but I do want to say that they've successfully invaded the more primitive parts of the world.

It is a satire of the following thread in the S+N forum which somehow devolved into an argument regarding the existence and nature of demons: