The practice involves placing arachnid-shaped decorations, often oversized, on the upper exterior of structures during the late October holiday. This tradition typically utilizes artificial spiders constructed from materials like plastic, metal, or fabric, and may involve affixing them to shingles, gutters, or other roof features. An example is the placement of a large, black, plastic spider with glowing red eyes on the peak of a residential dwelling.
This form of seasonal ornamentation contributes to the ambiance of celebratory events, adding a visual element intended to evoke feelings of fright and amusement. The placement of such items on elevated portions of buildings allows for increased visibility and a greater impact on observers. Historically, such decorations have been used to signify participation in communal festivities and to express individual creativity and engagement with the holiday spirit.