I really hate to be the guy that tells you this; but I feel like it would be a disservice not to. When you vacuum up a spider, the vast majority of the time, they survive. The little ones are even small enough to crawl right out of all of the debris in the tank, up the hose, and out the way they came in. Even the larger ones might lose a leg, but unless you have the brush going and it literally rips them apart; you're just giving them a place to hide until you leave. =\