Right now my neighbor has a feral cat and her litter of kittens. They are around 7-8 weeks old and she is planning to give them away. However she insists on keeping them locked in her garage of late because kittens can "suddenly become feral" if allowed outside.
Is there any truth to this claim?
I have almost no kitten experience, but Alley Cat Allies is the leading advocacy group in feral care. They say in the beginning of their Socialized Cat Guide:
Kittens who do not have any contact with humans after they are born will be feral, regardless of whether their mother is a lost house cat or a feral cat living in a colony. They will be frightened of people and demonstrate all of the signs of fear and anxiety that an adult cat would, like spitting, hissing, and running from human contact.
To become pets, they will need to be socialized, or taught to be comfortable around people. If the kittens are eight weeks or younger, usually just about anyone can socialize them by following some simple steps. Kittens between two months (eight weeks) and fourth months of age often take more time and skill to socialize. Learn how to determine kitten age.
Specifically, if your neighbor has not been regularly handling these kittens they are currently feral. They are still young enough to be socialized into pets if they are given to people who understand what a commitment this is.
[S]he insists on keeping them locked in her garage of late because kittens can "suddenly become feral" if allowed outside.
Your neighbor is technically wrong, but possibly doing the right thing for the wrong reasons. However, without proper socialization of the litter she is likely to end up with a colony of feral cats living in her garage.
According to the ASCPA, a feral cat is:
[A] cat born and raised in the wild, or who has been abandoned or lost and turned to wild ways in order to survive, is considered a free—roaming or feral cat. While some feral cats tolerate a bit of human contact, most are too fearful and wild to be handled.
The word feral also means "undomesticated."
In practice, the key differentiator in whether a cat will be feral or domesticated is the appropriate amount of human socialization at the right life stage. Access to the great outdoors won't intrinsically make a cat feral, nor will keeping them locked in the house (or garage) inherently domesticate them. However, any reduction in socialization caused by free-roaming away from human contact is likely to be sub-optimal for the domestication process.
I once had to help "house-train" feral kittens and their mother before they would be given away for adoption by the local RSPCA.
Initially all the kittens would hiss and spit at anyone who would try to go near them or run away and hide.
You need to play with them using a kitten-enchanter (a fishing rod with some elastic cord and furry toy for them to chase). Then they distracted by the furry toy and don't get bothered about being handled or climbing onto humans. Feeding time is the best way to socialize them to humans. Once they are busy drinking milk or eating cat chow, you can pet them.
Although "feral" is supposed to differ from "stray" in that the stray used to have an owner, feral cats have varying degrees of comfort around humans depending mostly on the type of place they grew up in (urban/suburban/village/etc). There are feral cats that like being around humans more, mainly because someone has been leaving out food for them, even playing with them, although they've never lived indoors. There also are house cats that haven't been properly socialized and handled, that will act more feral than cats classified as "feral".
Kittens, like all babies, are taught how to behave by their mothers. That includes trusting/not trusting humans. If your neighbor believes that feral status has to do with access or lack of access to outdoors areas, they're mistaken. It's contact with humans that "tames" cats, more easily so when they're very young, not indoor/outdoor status.
They would have a better chance of becoming friendlier/more used to humans even if they were outside (say, in a garden), but ideally in a safe place where they can observe and interact with people, see people giving them their food, and perhaps more importantly, smell humans and see they are no threat.
If your neighbor insists on keeping them in the garage, they should at least take time to introduce themselves to the cat and kittens, so as to get them used to humans.
