Not really related, but not a nice thought either!
I used to have a pet tarantula, despite being arachnophobic (therapy, and it helped by the way), I ceased owning one when my girlfriend refused to share a postcode with it, ( As said earlier they do have 'book' lungs and breathe by absorbing oxygen, they also have a very primitive curculatory system and no veins as such which means, despite being limited in size, if spiders of the tarantula family fall from a subsantial height there is a good possibility that they would be killed from the resulting impact as it may case them to simply rupture, at least, so I am told. Also despite having five eyes they have very limited eyesight and although having a vastly acute sense of vibration and taste (scent based) they are almost completely divorced from the outside world, in addition, if mine was a good example of their type, as clumsy as they could get. Since they are like this and add to that the fact that their web is so primative it cannot, unless it is interwoven into a mesh, support their own weight, its a wonder they are not all in stress counselling.)
One time I was on the computer, kinda like this, when I heard the sound of the spider's glass door opening slightly, I turned to see my spider, which had squeezed a couple of legs down the crack between the sliding plate and the side of its enclosure was trying to pry itself through, distressing as at the time it was living at the foot of my bed.
Naturally soon after I installed a catch on the doors.
Incidentally there are aproximately 2000 spiders in the average home.
All the best.
Randall