A predator trap is a natural hazard such as a tar pit. Predators would become attracted to struggling animals that have become entrapped in viscous or glutinous material, such as a heavy sedimentary deposit or tar and, in the process, become entrapped themselves. More predators, scavengers, insects and birds become attracted to this mounting accumulation of carrion, until a wide variety of animals are caught and ultimately killed by the hazard. This may happen many times over. Typically, the number of lured predators will greatly outnumber the prey, thus providing the name.
A famous example is the La Brea Tar Pits site. The Cleveland Lloyd Dinosaur Quarry may yet prove to be a further example. The Gobi desert dinosaur death traps may have been sauropod footprints that have been filled with a mixture of thick mud & sandstone in the former wetland.