There is an opinion among many that killing a cockroach attracts more of them. However, there is no proven scientific evidence to back this fact up. Yet such a phenomenon has often been noticed. This is especially the case when the roach in question has been killed by smashing it or it has been stepped on.
The smell of the dead cockroach may attract its comrades. This can be hypothesized as these insects are often attracted to the smell of dead objects; the same is true with cockroaches.
However, researchers found in a study that insects usually steer clear when they smell anything dead from their own breed. This means that cockroaches may be attracted to a dead butterfly but not a dead cockroach.
Does Killing Cockroaches Attract More?
Well, yes. Dead roaches attract more of their kin. If you kill a cockroach and let the carcass stay there for a while, you will see that a handful of cockroaches have approached the spot. They may either sniff around and crawl back to their corners or they may carry the dead one back with them.
Despite the study cited above claiming otherwise, there is hard evidence that cockroaches do congregate around the dead body of their fallen comrade. A kind of acid called Oleic Acid is released from the body of a dead cockroach and while that smell may be pungent for us humans, it serves as a signal for the alive roaches out there.
They follow that smell to figure out the location of the dead cockroach. Some claim that the smell serves as a signal of danger for the rest of the roaches to stay away from the zone. But it is highly probable that they will indeed covertly approach the area and once they deduce that there is no danger to their lives in their immediate vicinity, they will go near the carcass and gather.
Why Does Killing Cockroaches Attract More?
The question of whether dead roaches attract other roaches or not is a topic of contention as clearly there are opinions supporting both sides of the argument. But by maintaining a neutral ground, it is easier to investigate the possible reasons behind roaches gathering around the dead body of their fallen community member.
Here are 3 reasons, why that happens:-
Secretion in Cockroach Droppings
If a cockroach is killed by squishing or having been stepped on, the insides all spill out. These contain the guts, a whitish fluid called hemolymph, and also their feces. Now these feces contain a kind of secretion that cockroaches leave behind to inform others of a habitable place.
So when you smash a cockroach, others nearby may catch a whiff of this positive pheromone before they smell the oleic acid. This will attract the live cockroaches to a possible safe shelter where they can establish a colony.
Dead Cockroach Turned Food
While it is true that cockroaches will avoid an area when they smell oleic acid, it is also true that hunger can make insects do anything. That includes making a dinner out of a dead brother.
Yes, cockroaches do cannibalize if there is no other food available and for this reason, they may congregate around the body of a dead cockroach and feast on it.
The body of a dead cockroach emits a pungent and acidic smell due to the presence of Oleic acid. This is often termed the “death stench”. While the odor from one dead roach will never make it to your nose unless you purposefully try to sniff it from up close, this smell is potent for the roaches lurking around.
They can smell this from a distance and it warns them of a fallen comrade and possible danger. So, they may initially avoid the area but if the smell continues to linger, they will approach the carcass in masses.
Cockroaches secrete other kinds of pheromones such as when female cockroaches emit a mating pheromone to attract a whole bunch of male cockroaches. There are scientific proofs to back that this indeed happens.
But that is not the case with cockroaches gathering around dead carcasses of other cockroaches as nobody knows for sure if it happens because of the reason they think it does.
However, one fact is certain and that is if you see more roaches emerging after you kill one, then your house may be infested and you should look for permanent methods of getting rid of these insects that are infamous for being carriers of germs.