Probably because the bears can see or smell them, Ebbie. Humans, especially in the dark, aren't that smart.

But I ask yet again, how vicious do you want to get? Do you want to incapacitate or kill? Remember, legally you have to have control over what you use AND you cannot harm someone who is fleeing because then the threat is over (no longer "imminent").

You COULD surround your home with a moat filled with pirahnas (goldfish in Canada because they're nicer) and alligators (frogs in Canada), have a portcullis and an oubliette, "murder holes", and a poison gas spray. Outside you could put fougasse. But you might find it difficult to have friends over for an evening....

Personally, I prefer a nightstick or a section of wooden closet rod about 24 inches long (or a 3 or more D-cell Maglight). But I know how to use those. I can break the wrist of the hand holding the gun and then seriously injure, incapacitate, or even kill the person attacking me. No holes in the walls and furniture, no burn marks, no toxic chemical spills -- perhaps just a few of those pesky bloodstains which a little hydrogen peroxide can fix right up.

Whatever you select, you need the will to use it. You KNOW you will injure or kill another human being -- oven cleaner in the face is probably going to blind the person, as is paint or car starting fluid (if they're smoking that could also set them on fire). Could you live with yourself knowing that you robbed someone of their sight or permanently crippled them? Could you live with the idea that you inadvertently took the life of another, even if you were cleared of wrongdoing by the law?

People are taught from childhood, from infancy, that hurting or killing others is wrong. If you cannot overcome this conditioning to the extent that you would attack someone all out, no holds barred, no quarter given, if you are attacked -- AND you are willing to learn to use your chosen "weapon" effectively and without hesitation -- don't do it. Invest instead in a set of GOOD locks, GOOD doors and a cell phone.