Kitten season is here, and Best Friends Animal Society, the nation's largest no-kill shelter, is inundated with the furry little felines.

It's an around-the-clock operation with nearly 200 kittens that require bottle-feeding every few hours.

There's no denying the kittens are adorable — especially when they're wrapped into little "purritos" like the ones above — but kitten season is a national problem.

From February through November, thousands of kittens are born in the U.S., and the majority of them end up in shelters without their mothers, still weeks away from weaning.

Taking care of the helpless animals can be overwhelming for many shelters, so the kittens are often euthanized upon intake.

Most of these kittens are born to feral cats that haven't been spayed or neutered.

"Recent surveys indicate something like 91 percent of pet cats are sterilized, which suggests that the vast majority of unweaned kittens are born to free-roaming, unowned community cats," Holly Sizemore, director of national programs, community programs and services, said in a news release.

If you find a litter of kittens, Sizemore says one of the best things you can do is simply leave them alone because their mother is often nearby, but another effective ways to save kittens is to prevent them from being born in the first place. That's why Best Friends and numerous other shelters and animal-welfare organizations trap-neuter-return programs.

bottle-feeding a kitten

Photo: Sarah Kichas/Best Friends Animal Society

What is trap-neuter-return?

TNR involves humanely trapping cats in a colony and then getting them spayed/neutered, vaccinated for rabies and marked for identification via eartipping. Kittens and social cats may be adopted into homes while the feral ones are returned to their colony.

It's not about rescuing cats — it's about population control, lowering euthanasia rates and creating better lives for outdoor cats. It allows the animals to live out their natural lives while eventually reducing the colonies to zero.

TNR has been practiced in the United States and Europe for decades, and studies show that it not only improves cats' lives, but also those of the people who live around them.

While sterilizing cats prevents more kittens from being born, it also decreases the chance of cats developing certain cancers, and when mating behaviors cease, so does the yowling, spraying and fighting that bothers neighbors.

"I think there are several amazing benefits for communities that arise after they embrace Trap-Neuter-Return," said veterinarian Julie Levy. "One of the most substantial ones is a resolution of the conflict that can surround cats in neighborhoods. Once residents understand that something is being done to control the cat population, they usually embrace having a trap-neuter-return program there."

kitten in cage

Photo: Dwight Smith/Shutterstock

Is TNR the best method to control cat populations?

While TNR is practiced in communities across the nation, there are other approaches to dealing with feral cats.

In many areas, feral cats are trapped and killed; however, it's an endless cycle.

While killing feral cats temporarily reduces the population in an area, surviving cats will continue to breed, and other cats move into the now-available territory in a phenomenon known as the vacuum effect. The same thing occurs when cats are trapped and relocated.

And while the idea of finding all cats a forever home is a nice one, the reality is that not all cats are fit for adoption.

Many feral cats have lived outside their entire lives and have had little interaction with people. Attempts to socialize them can work, but it's typically more effective to find homes for social cats and return the rest to their colony without trying to change their natural behaviors.

The Humane Society, the American Society for the Prevention of Cruelty to Animals, Best Friends Animal Society, Alley Cat Allies and numerous other organizations support trap-neuter-return programs as the most effective way to approach feral cats; however, TNR isn't without critics.

Much of the criticism is focused on the impact outdoor cats have on wildlife, especially the killing of birds.

"TNR advocates see the cat deaths as individual tragedies. But birds somehow just die as populations, or species. Because the cats do their killing out of our sight, and without our direct intervention, people fail to see that those other deaths are equally individual,” writes Richard Conniff, author of “The Species Seekers: Heroes, Fools and the Mad Pursuit of Life on Earth."

Still, more than 80 percent of Americans believe it’s more humane to leave a cat outside than to kill it.

Want to help cats in your area? Best Friends Animal Society has a variety of useful tools to help you implement a community TNR program, and the ASPCA has numerous tips and guidelines to get you started.

What's it like caring for nearly 200 kittens? In the video below, Best Friends shows all the work that goes into taking care of their sudden influx of furbabies.

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Laura Moss writes about a variety of topics with a focus on animals, science, language and culture. But she mostly writes about cats.

How trap-neuter-return programs save cats
With kitten season here, animal lovers are working to limit births, saving millions of cats in the process.