How to Kill a Big Spider. Spiders can be a nuisance and downright scary. Seeing a big one on your wall can make you wonder what to do. If you smash it, it could leave a big mark. If you spray it, it might not die and could still crawl away. Follow these steps for the easiest way to kill a big spider.
Identify the spider as closely as you can. If it is a common household or garden spider, you may want to leave it alone or catch it in a jar and put it outside.
Determine if it is a poisonous spider such as the black widow or brown recluse. The black widow has a round sac-like body with a head on top and a red diamond-shaped mark on its belly. The brown recluse has a violin-shaped body.
Find your vacuum cleaner, and bring it to the room where the spider is located. Ask someone to keep an eye on the spider while you are gone so you don't lose track of it.
Turn on your vacuum cleaner and suck the spider up through the hose. Don't worry-it won't propagate inside your vacuum cleaner. The impact from the vacuum cleaner kills it.
Grab a spray bottle of bug spray, hair spray or some other noxious chemical, if you don't have a vacuum cleaner. Also, grab something hard and flat.
Spray the spider with the spray bottle. This slows the spider down and hopefully makes it fall from the wall to the floor so you can flatten it. If you don't want to use a spray bottle, that is OK. However, the spider might escape before you kill it. Also, the spider could leave a mark on your wall.
Pick the spider up in some toilet paper and flush it down the toilet to kill it. Now you can relax.