The spider

I wish I could. Can you?? Maybe it represented some kind of "darkness" which enveloped her [life].

Finally, I could saw this movie three days ago, on TV.
So I'm not the one who have noticed this macabre scene.
It seems that when the spider falls, the life of Margaret ends, perhaps also Frank had think that, so he killed the animal with anger.
I was displeased when I saw blood come out from her mouth!

I also thought the spider symbolized the spectre of death originally. In retrospect though, I can see where it might also simply represent her. He crushes the spider same as his torments led to her demise.

Could go either way. Actually, I still favor the death metaphor, with his squishing blow showing just how impotent his machismo was in the end.

I would like to read the spider as somehow relating to Ovid's telling of the myth of Arachne, the mortal weaver who boasted she was a greater weaver than the goddess Minerva. There's only one catch...Margaret is nothing like the mythical Arachne. Arachne was something of a super-mortal who overstepped her boundaries with the gods. (Frank is much more this role...) However, in the myth, Arachne realizes that she has been out of line with the gods and chooses to kill herself. Minerva takes pity on Arachne and saves her, changing her into a spider. So spiders are sometimes interpretted as an escape or a reincarnation into a second chance; a kind of redemption granted by the gods. More significantly, perhaps, it is often considered bad luck in Western cultures to kill a spider because they represent Arachne. So Frank killing the spider might more accurately reflect his ongoing bad luck and bad choices.

Wait...the spider appeared to fall to the floor. After Margaret died, it was back at "fist height" for the kill? Could Franks grief-riddled mind have been acting up? Was there a spider at all? After all, he did hear a floorboard creak (in an otherwise empty house) after calling out Margarets name afterward.

Well, Spiders webs trap prey, she trapped her emotions, and the appearance of webs as a pattern could resemble a files pattern which took the life of her late husband

http://tinyurl.com/privacy-06

My opinion is that killing the spider was something he could control.
He could not control Margaret, could not stop her from dying but whether the spider lived or not - that was his down to him and he liked being in control didnt he?
Plus he was angry of course.

Maybe the spider was Eric.