Crawl Like a Snake

Dumb monsters are more a convention of video games, where limits on enemy AI require they conveniently forget they layout of a room and dismiss any noise after a certain amount of time. In extreme cases, they will forget having seen an enemy or watching a friend die. But even in Tabletop games monsters are often oblivious as to what’s going on in the next room and can easily be fooled by the most obvious of distractions.