Assuming I suck up a bunch of dead bugs and a live spider. Would the spider be happy in there? Vacuum bags are air-permeable, so plenty of air for it to breathe. Alternatively, would a smaller dustbuster make any difference?
Would it find its way out? If not, how long before it is stone dead and I can change the bag without fear of creepy crawlies making their way out?
vacuum a small shoe or a rolled up magazine before changing the bag.
Do not use a dust buster. They do not have fine filters, and the bugs can fly out the exhaust vents.
Funny that this exact question was asked (and answered) in a Q&A column in a German newspaper supplement (decent, but of course not nearly as good as the Straight Dope) recently. They essentially said that it was theoretically possible for spiders to survive vacuuming, but unlikely, since they hit the inside of the hose many times at considerable speed when they get sucked in. The smaller the spider, the higher the probability for the spider to survive, so it’s conceivable (so said the supplement) that a few ones might make it. And yes, it will crawl out and take revenge.
You definetly have to keep posting here. 
Agreed.
The placement of a vacuum cleaner’s centrifugal fan (or this) has a large effect on the survival rate of sucked up bugs. In some vacuums, such as shopvacs, the blades, which spin at upwards of 10krpm, are positioned beyond the dust collection bin. In others, everything must pass through the fan blades to get to the dust receptacle.
While bumping down a vacuum hose at 25mph might stun an bug, impacting a four inch fan running at 10krpm, 110mph at the perimeter, is probably certain death.
Squink, are there really vacs that make the dirt go throught the fan? isn’t that a engineering nightmare with the dirt piling on the blades (don’t look at your ceiling fan now) and messing with the mechanism and all that?
(and thanks, guys)
Yes there are. They design the impeller to handle it, typically with tough plastic blades like those in my first link. The post-bag fans usually look like those in my second link. Both designs have problems. With the fan placed after the bag, you can lose efficiency pretty fast as the bag filter gets coated with dust and starves the fan for air. However, not having to worry about crap hitting the fan, they can use a more elegant blade design, and get a higher pressure rise per rpm than with the pre-bag fans.
If your vacuum makes a horrible noise when you suck up a penny, sans beater bars, you’ve can be pretty sure you have a unit with a pre-bag fan.
Most of your older uprights with the bag hanging off the back are pass-through. You can hear the dirt hitting the impeller.
I doubt anything will survive long if it’s being whipped around in a bunch of dirt at 100 mph. Kind of like being stuck in a tornado.
I once vacuumed up a fly and when I empted the bag I found it still moving. How long it would have lived, I can’t say.