Spiders are really dumb little bugs, and don't even know they are wandering into your house.
They are doing what they do, hunt for bugs to eat, or a girlfriend.
There are some spiders like house spiders that simply live in the house with you.
I fear spiders aren't the smartest of creatures.
They think they are doing us a favor by catching the bugs .
It's invading territory. Don't they get the idea that they will be killed?