The Pinaviztli is an insect of ill-omen known to the Aztecs. It looks like a spider the size of a mouse, smooth and hairless and fat-bodied, red and black in color.
The entrance of a pinaviztli into a house is a bad omen. It can be countered in one of two ways. The first is to draw a cross on the floor pointing to the four cardinal directions. The pinaviztli is placed in the middle, spat on, and asked, “Why did you come? I want to know, why did you come?” If it goes north, it is a sign of coming death. Any other direction heralds a lesser affliction. The insect is told “Go your way, I don’t care about you”, and it is dropped off at the nearest crossroads.
The second ritual consists of passing a hair through the pinaviztli’s body and tying it to a stick, leaving it dangling for a day. If it is gone by the next day, then harm is sure to befall the household. If it is still there, the people spit on it and are reassured that nothing will happen.
Sometimes a pinaviztli foretells the gift of good food.
Nuttall, Z. (1895) A Note on Ancient Mexican Folk-lore. The Journal of American Folklore, v. 8, no. 29, pp. 117-129.