Properly caring for a feral cat colony can take a bit of time and money, but can be incredibly rewarding. If you are taking certain precautions to minimize nuisance behaviors, you can maintain a colony without disturbing neighbors. The most important step is to spay/neuter all the cats in your colony (fixing only some of the cats will not alleviate behaviors associated with mating, like spraying and yowling; and it will not keep the population down).
To minimize the number of other wild critters that are trying to join your colony, establish feeding times when it’s light out, and don’t leave food out overnight. This will discourage raccoons, opossums and skunks from moving into the neighborhood.
Offering your colony’s cats a shelter that allows them to get out of the cold and heat is another easy way to give these cats a more comfortable life. OAR sells shelter kits; and there are several plans for shelters online as well.