It's a safe bet that if they know about us at all they'll just stay away from us. Our media is filled with depictions of us killing aliens. There's little reason to think we'd accept them. We can't even get along with/accept other humans. Some people's first instinct will be to shoot them. Others will want to lock them up and experiment on them.

If aliens did come here they'd have to be very brave, powerful enough not to worry about what we'd do, or unaware of what we are.

I'm not too worried they'd kill us to protect themselves though. At the rate we're going, we'll kill ourselves off along with every other living thing on the planet long before we get out of our own solar system.

>If aliens did come here they'd have to be very brave, powerful enough not to worry about what we'd do

If aliens had the technology to visit us right now, the latter is a given.

You don't have to assume anything crazy. You can create a planet killer by simply accelerating a decently massive object at relativistic speeds and firing it at earth.

The most horrifying aspect of the hypothesis as depicted in the Dark Forest book is that it was simply the job of a low-level bureaucrat to identify "low-entropy entities which lack the hiding gene" within their region of the galaxy and allocate a basic bottom-shelf munition to "cleanse" it.

However, humans were aware of this possibility and had spent centuries reorganizing the solar system to have a measure of resilience to it. So, to humanity's great credit, he had to go get permission from his supervisor for to deploy a next-tier solution.

"Why would anyone travel across town (i.e., the galaxy) just to step on an anthill?" We have a whole industry dedicated to exterminating any other life that invades "our" living space. It's considered an unremarkable necessity.