1. Black Cats: In ancient Egypt, the Goddess Bast was a black, female cat. Christians, wanting to rid society of all traces of other religions, convinced the ignorant that black cats were demons in disguise and should thus be destroyed. In the process, they also destroyed the kindly ladies who cared for the cats, believing them to be witches. Being demons, a black cat crossing your path would create a barrier of evil, cutting you off from God and blocking the entrance to heaven.
2. It's bad luck to walk under a ladder: A leaning ladder forms a triangle with the wall and ground. Triangles represent the Holy Trinity, and violating the Trinity by breaking it (walking through it) would put you in league with the devil himself. Considering what Christians did to those who were considered to be in league with the devil, it's hardly surprising that leaning ladders were avoided at all cost.
Bearing that in mind, this is Blue, my completely black except for a tuft of white on his chest cat. I don't let him roam outside because the rural area I live in is full of wild animals which might prey on him. So I built a fairly large enclosed pen for him and my other cat, Possum, which Blue absolutely loves being in.
And this is one of my projects, I want to take down this old TV antenna and turn it into a flagpole with maybe a little circular garden around it, or white landscape rock, or whatever. It doesn't matter right now. In any case, I put the ladder up to take it down, thinking, "I know I can, I know I can, I know I can", but I couldn't, because I am afraid of heights. I can't ask my older son to get it down, because already has a collar around his neck from a fall. I asked my younger son, but he couldn't find the right bit for the screwdriver. I asked my husband, but he hasn't gotten around to it yet. (You know how that goes!)
So there the ladder stands. And right under it I walked as I brought Blue inside, holding that black cat. I think I really need to watch what I do for the next little while, because I'm not really superstitious, but there's no point in tempting fate, is there?