Cats in New York City are an invasive species that are a plague to the animal kingdom. It is well documented that these bloodthirsty psychopaths are responsible for the murder of billions of innocent and helpless creatures a year. They devastate ecosystems and ruin the lives of many animals that are simply trying to survive, hunting many to the brink of extinction. Despite knowing this, the human community has done nothing to help. They, through ignorance or indifference, ignore the reality of the plight of animals, sympathizing with these monsters due to their cuteness.
The critters in the city (pigeons, squirrels, chipmunks, rats, etc) have finally banded together and decided that ENOUGH IS ENOUGH! For too long, they have sat back and waited for humans to curb the feline population, while suffering the loss of their loved ones and friends. Rather than compete with each other for resources such as food and shelter, they have realized that they have a mutual interest in standing against a common enemy. This "rodent mafia" have agreed in animal terms to cooperate and come to the defense of each other through a mutual-species agreement, as well as to take down their hated enemies whenever and wherever possible.
Communication is defined as the transmission of information. Every species has its own species-specific body, vocal language and odours in which they use to "talk" with others of their kind. Inter-species communication is rare. Assuming they were intelligent enough, what natural mechanism can different species of prey animals develop the ability to communicate with each other in order to organize against a super-predator?