How New York City is getting rid of Rats

[Tom.G]

A creative exterminator is filling their burrows with Carbon Monoxide, then collapsing the burrows. Apparently other rats can smell the decaying ones, decide they don't like the neighborhood, and either move on or don't try to homestead there.

Short article with way too many ads at:
https://www.businessinsider.com/nyc-exterminator-dead-rat-bodies-carbon-monoxide-2023-10

Cheers,
Tom

 

[kuruman]

Apparently other rats can smell the decaying ones, decide they don't like the neighborhood, and either move on or don't try to homestead there.

So they move to New Jersey?

 

[BillTre]

There probably a set of chemicals that could mediate this response.
The lab chemical catalogues already have things like cadaverine which is used to train cadaver seeking dogs.
There are other chemicals with similar effects.
The dead rat avoidance behavior could be due to a general sets of chemicals of death, or a set specific to dead rats, or they may just be more sensitive to a particular chemical in the mix.
More behavioral studies (or knowledge if the studies have already been done) could distinguish some of these alternatives.

Irregardless, it should be possible to reproduce the effect with just chemicals.
What the rats long term responses would be is not clear.

 

[Laroxe]

Getting rid of rats in N.Y. I seriously doubt it. Getting rid of 100 nests? colour me unimpressed. They have been gassing and poisoning them for a long time. NY has an extensive sewer system that needs maintenance. Carbon monoxide is odourless and just as deadly to people, with no warning smell it would probably kill thousands, along with their pets of course which are also used as a control method.
While the smell of dead rats is terrible, apparently the rats like Eucalyptus or Peppermint even less, neither do they like the effects black pepper, cayenne pepper or ammonia on them, unfortunately none of these are totally reliable. Rats will often cannibalize dead rats or even the young of other rats, perhaps to reduce the risk of attracting predators. Most exterminators appear to think that the smell can attract other rats, a dead rat in a colony doesn't get rid of the others. They do however, quickly identify things that might be dangerous and avoid that. Leaving dead rats to decompose represents a potential health hazard to humans as well as other animals.

We have been trying to exterminate rats for centuries, they are destructive and represent a serious health hazard, we have even had humans who specialise in their eradication, and still do, using a wide range of control methods These now even include traps described as humane, the rats can be trapped alive and released some distance away. If these rats have young, these will starve or be cannibalized by others in the colony, rats released in the wild, rarely live beyond a week due to unknown predators or even other rats. This usually ensures they live that week in a state of abject terror, so it's not really humane, releasing them near human habitation could lead to prosecution. This story seems marginally less credible than the pied piper and probably is supposed to serve the same purpose, to entertain.