Do spiders have brains like if they come into your house are they aware you will try anything to get rid of them?

Spiders do not harbor any prejudices about human beings. Generally speaking, they do not have any concept of a house, or of a house as the lair of a territorial animal. On top of that, only a relatively small number of species of spiders have good enough vision to see a house or a human.

Spiders primarily are interesting in getting insects to eat. They bite prey. Occasionally they may have to bite something to defend themselves against it. So if somebody gets bitten it will ordinarily be for one of two reasons: (1) The spider has made a prey mistake. If the tip of somebody's finger was touched to the wall a Huntsman spider was resting on then it might see only the end of the finger and take it to be some kind of caterpillar. If a human touched a finger down on a spider web, the spider (who is legally blind) might rush out and bite it. (2) The spider is getting hurt by something the human is doing, or maybe it is protecting its eggs or baby spiders, so it will give a defensive bite.

The only spiders that seem to have a real interest in human beings are the jumping spiders, and that is because their vision is so good that they can actually see us. Once a human comes near to them, they will keep their bodies turned so they can watch us. Some kinds are very timid and will keep a distance from humans, but a few species seem to be so curious about us that they will jump from their spot on the wall to a finger held at a tempting distance and then they will jump from finger to finger and give the whole hand a good exploration.

Jumping spiders, and some other hunting spiders, seem to have enough of a brain to learn that the human is not in attack mode. In the beginning they will act scared, but when nothing bad happens they will calm down.

Jumping spiders sometimes come into houses through open Windows. Perhaps they followed a fly inside, or perhaps they just made a random exploration that led them through the window. They do not seem to have any prejudice that makes them think humans would attack them for no good reason. If they could think well enough, they might expect that humans would welcome them in to kill the buzzing house flies and the biting mosquitos.