IMON often receives requests to remove cats from certain areas. However, removing or relocating feral cats is both ineffective and inhumane due to a phenomenon called the "vacuum effect."

 

WHAT IS THE VACUUM EFFECT?

When cats are removed, whether through killing or relocation, it creates a temporary void in the habitat. This empty space attracts new cats, either from nearby territories or those born from the remaining population, to move in and take advantage of the same resources that attracted the original group—like shelter and food. The result is an endless cycle where the population rebounds, often to even higher numbers. This "vacuum effect" is a well-documented scientific phenomenon observed across various species.

​

THE SCIENCE BEHIND IT

Scientific research and years of failed attempts by animal control agencies have shown that "catch and kill" or "catch and remove" approaches are futile. Removing cats does not address the resources that sustain them, and without intervention, the population will quickly recover and grow, as the remaining cats reproduce at higher rates.

Biologists have observed this phenomenon in species such as mountain lions, possums, badgers, and raccoons. One researcher noted that removing resident mountain lions only allowed new lions to move in and claim the territory. Similarly, when cats are removed, more will eventually take their place, leading to a continuous and costly cycle of trapping and killing without a long-term solution.

​

WHAT CAN BE DONE INSTEAD?

If you’re dealing with issues caused by a feral cat colony, removing them will only make matters worse. Unmanaged colonies may cause problems like fighting, noise, or property damage. However, these behaviors can be addressed without removing the colony, which only invites a larger, unmanaged group to move in.

 

IMON offers effective solutions, such as Trap-Neuter-Return (TNR), to help manage these colonies humanely and prevent further issues. Contact us to discuss strategies for improving the behavior of the feral cats in your area without falling into the trap of the vacuum effect.