A cat lover in Brooklyn is making a difference by providing care for the outdoor cat population while helping to make sure it doesn't grow unchecked.

Will Zweigart and his wife founded the nonprofit group Flatbush Cats two years ago. Its goal is to make sure every cat in Flatbush is spayed or neutered, preventing them from reproducing.

Zweigart says outdoor cats can easily have a dozen kittens in a year, and without loving homes they're left to fend for themselves in the wild -- where they can be hit by cars or struggle to find food.

In addition to getting the cats fixed, the group makes sure they get medical care and -- if they're friendly -- adopted.

Zweigart says his work is funded by cat lovers around the world, many of whom donate money, volunteer and open their hearts and homes.

Experts say there are more than 500,000 cats on the streets of New York City without homes.