The Scent of Death
“There is another factor,” Dave added, twisting the knife. “When you crush a roach, it releases oleic acid. It’s a chemical that smells like death to us, but to other roaches? It’s complicated. Sometimes it warns them away, but the scent of a crushed roach can also attract others to feed on the carcass if you don’t clean it perfectly.”
“But I used bleach!” Mark protested. “Did you clean the tread of your boot?” Dave asked. “Did you scrub the grout lines with a toothbrush? Because if you missed a spot, the pheromones stay. And the eggs stay.” Mark realized he had walked all over the house with that boot, essentially drawing a map for the roaches.