• a growing population of cats.
• frequent and loud noise from fighting and mating behavior.
• strong foul odors from unneutered male cats spraying to mark their territory.
• spread of disease and infections.
• flea infestations.
• visible suffering from dying kittens and injured adults.
• food source for other urban predators, including raccoons, stray dogs and coyotes.

In addition, the shelters in a community with a large feral cat population may experience:

• higher intake rates of cats into shelters due to the rescue of feral kittens and the capture of feral adults.
• higher euthanasia rates for all cats due to the unadoptability of feral adults and the necessity to euthanize adoptable animals due to limited cage space.
• higher animal control costs due to trapping efforts and/or costs associated with caring for and euthanizing feral cats.
• a constant rate of nuisance complaints about feral cats.